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1 #LyX 1.4.1 created this file. For more info see http://www.lyx.org/
2 \lyxformat 245
3 \begin_document
4 \begin_header
5 \textclass book
6 \language english
7 \inputencoding auto
8 \fontscheme default
9 \graphics default
10 \paperfontsize default
11 \spacing single
12 \papersize a4paper
13 \use_geometry false
14 \use_amsmath 2
15 \cite_engine basic
16 \use_bibtopic false
17 \paperorientation portrait
18 \secnumdepth 3
19 \tocdepth 3
20 \paragraph_separation indent
21 \defskip medskip
22 \quotes_language english
23 \papercolumns 1
24 \papersides 2
25 \paperpagestyle default
26 \tracking_changes false
27 \output_changes true
28 \end_header
29
30 \begin_body
31
32 \begin_layout Chapter
33 Preparing a model for reuse
34 \begin_inset LatexCommand \index{reuse}
35
36 \end_inset
37
38
39 \begin_inset LatexCommand \label{cha:model2}
40
41 \end_inset
42
43
44 \end_layout
45
46 \begin_layout Standard
47 There are four major ways to prepare a model for reuse.
48 First, you should add comments to a model.
49 Second, you should add methods to a model definition to pass to a future
50 user your experience in creating an instance of this type which is well-posed.
51 Third, you should parameterize the model type definition to alert a future
52 user as to which parts of this model you deem to be the most likely to
53 be shared.
54 And fourth, you should prepare a script that a future user can run to solve
55 a sample problem involving an instance of the model.
56 We shall consider each of these items in turn in what follows.
57 \end_layout
58
59 \begin_layout Section
60 Adding comments
61 \begin_inset LatexCommand \index{comments}
62
63 \end_inset
64
65 and notes
66 \begin_inset LatexCommand \index{notes}
67
68 \end_inset
69
70
71 \end_layout
72
73 \begin_layout Standard
74 In ASCEND we can create traditional comments for a model -- i.e., add text
75 to the code that aids anyone looking at the code to understand what is
76 there.
77 We do this by enclosing text with the delimiters
78 \family typewriter
79 (*
80 \family default
81
82 \begin_inset LatexCommand \index{(*}
83
84 \end_inset
85
86 and
87 \family typewriter
88 *)
89 \family default
90
91 \begin_inset LatexCommand \index{*)}
92
93 \end_inset
94
95 .
96 Thus the line
97 \end_layout
98
99 \begin_layout LyX-Code
100 (* This is a comment *)
101 \end_layout
102
103 \begin_layout Standard
104 is a comment in ASCEND.
105 Traditional comments are only visible when we display the code using the
106 Display code tool
107 \begin_inset LatexCommand \index{Display code tool}
108
109 \end_inset
110
111
112 \begin_inset LatexCommand \index{tool, Display code}
113
114 \end_inset
115
116 in the Library window or when we view the code in the text editor we used
117 to create it.
118
119 \end_layout
120
121 \begin_layout Standard
122 We suggest we can do more for the modeler with the concept of Notes, a form
123 of "active" comments available in ASCEND.
124 ASCEND has tools to extract notes and display them in searchable form.
125 \end_layout
126
127 \begin_layout Standard
128 \begin_inset Marginal
129 status collapsed
130
131 \begin_layout Standard
132 notes are active comments
133 \begin_inset LatexCommand \index{comments, active}
134
135 \end_inset
136
137
138 \end_layout
139
140 \end_inset
141
142 In Figure
143 \begin_inset LatexCommand \ref{fig:model2.vesselWithNotes}
144
145 \end_inset
146
147
148 \noun off
149 we show two types of notes the modeler can add.
150 Longer notes are set off in block style starting with the keyword
151 \family typewriter
152 \noun default
153 NOTES
154 \family default
155 \noun off
156 and ending with
157 \family typewriter
158 \noun default
159 END NOTES
160 \family default
161 \noun off
162 .
163 In this model, we declare two notes in this manner: (1) to indicate who
164 the author is and (2) to indicate the creation date for this model.
165 Note that the notes are director to documenting SELF, which is the model
166 itself -- i.e., the vessel model as a whole object.
167 The object one documents can be any instance in the model -- any variable,
168 equation or part.
169 The tools for handling notes can sort on the terms enclosed in single quotes
170 so one could, for example, isolate the author notes for all the models.
171 \end_layout
172
173 \begin_layout Standard
174 \begin_inset Float figure
175 wide false
176 sideways false
177 status open
178
179 \begin_layout LyX-Code
180 REQUIRE "atoms.a4l";
181 \end_layout
182
183 \begin_layout LyX-Code
184 MODEL vessel;
185 \end_layout
186
187 \begin_layout LyX-Code
188 NOTES
189 \end_layout
190
191 \begin_layout LyX-Code
192 'author'SELF {Arthur W.
193 Westerberg}
194 \end_layout
195
196 \begin_layout LyX-Code
197 'creation date' SELF {May, 1998}
198 \end_layout
199
200 \begin_layout LyX-Code
201 END NOTES;
202 \end_layout
203
204 \begin_layout LyX-Code
205 (* variables *)
206 \end_layout
207
208 \begin_layout LyX-Code
209 side_area "the area of the cylindrical side wall of the vessel",
210 \end_layout
211
212 \begin_layout LyX-Code
213 end_area "the area of the flat ends of the vessel"
214 \end_layout
215
216 \begin_layout LyX-Code
217 IS_A area;
218 \end_layout
219
220 \begin_layout LyX-Code
221 vessel_vol "the volume contained within the cylindrical vessel",
222 \end_layout
223
224 \begin_layout LyX-Code
225 wall_vol "the volume of the walls for the vessel"
226 \end_layout
227
228 \begin_layout LyX-Code
229 IS_A volume;
230 \end_layout
231
232 \begin_layout LyX-Code
233 wall_thickness "the thickness of all of the vessel walls",
234 \end_layout
235
236 \begin_layout LyX-Code
237 H "the vessel height (of the cylindrical side walls)",
238 \end_layout
239
240 \begin_layout LyX-Code
241 D "the vessel diameter"
242 \end_layout
243
244 \begin_layout LyX-Code
245 IS_A distance;
246 \end_layout
247
248 \begin_layout LyX-Code
249 H_to_D_ratio "the ratio of vessel height to diameter"
250 \end_layout
251
252 \begin_layout LyX-Code
253 IS_A factor;
254 \end_layout
255
256 \begin_layout LyX-Code
257 metal_density "density of the metal from which the vessel
258 \end_layout
259
260 \begin_layout LyX-Code
261 is constructed"
262 \end_layout
263
264 \begin_layout LyX-Code
265 IS_A mass_density;
266 \end_layout
267
268 \begin_layout LyX-Code
269 metal_mass "the mass of the metal in the walls of the vessel"
270 \end_layout
271
272 \begin_layout LyX-Code
273 IS_A mass;
274 \end_layout
275
276 \begin_layout LyX-Code
277 (* equations *)
278 \end_layout
279
280 \begin_layout LyX-Code
281 FlatEnds:end_area = 1{PI} * D^2 / 4;
282 \end_layout
283
284 \begin_layout LyX-Code
285 Sides:side_area = 1{PI} * D * H;
286 \end_layout
287
288 \begin_layout LyX-Code
289 Cylinder:vessel_vol = end_area * H;
290 \end_layout
291
292 \begin_layout LyX-Code
293 Metal_volume:(side_area + 2 * end_area) * wall_thickness = wall_vol;
294 \end_layout
295
296 \begin_layout LyX-Code
297 HD_definition:D * H_to_D_ratio = H;
298 \end_layout
299
300 \begin_layout LyX-Code
301 VesselMass:metal_mass = metal_density * wall_vol;
302 \end_layout
303
304 \begin_layout LyX-Code
305 END vessel;
306 \end_layout
307
308 \begin_layout LyX-Code
309
310 \end_layout
311
312 \begin_layout LyX-Code
313 ADD NOTES IN vessel;
314 \end_layout
315
316 \begin_layout LyX-Code
317 'description' SELF {This model relates the dimensions of a
318 \end_layout
319
320 \begin_layout LyX-Code
321 cylindrical vessel -- e.g., diameter,
322 \end_layout
323
324 \begin_layout LyX-Code
325 height and wall thicknes to the volume of metal
326 \end_layout
327
328 \begin_layout LyX-Code
329 in the walls.
330 It uses a thin wall assumption
331 \end_layout
332
333 \begin_layout LyX-Code
334 -- i.e., that the volume of metal is the area of
335 \end_layout
336
337 \begin_layout LyX-Code
338 the vessel times the wall thickness.}
339 \end_layout
340
341 \begin_layout LyX-Code
342 'purpose' SELF {to illustrate the insertion of notes into a model}
343 \end_layout
344
345 \begin_layout LyX-Code
346 END NOTES;
347 \end_layout
348
349 \begin_layout Caption
350 Vessel model with Notes added (model vesselNotes.a4c
351 \begin_inset LatexCommand \index{vesselNotes.a4c}
352
353 \end_inset
354
355 )
356 \begin_inset LatexCommand \label{fig:model2.vesselWithNotes}
357
358 \end_inset
359
360
361 \end_layout
362
363 \end_inset
364
365
366 \end_layout
367
368 \begin_layout Standard
369 A user may use any term desired in the single quotes.
370 We have not decided yet what the better set of terms should be so we do
371 not as yet suggest any.
372 With time we expect the terms used to settle down to just a few that are
373 repeated for all the models in a library.
374 \end_layout
375
376 \begin_layout Standard
377 \begin_inset Marginal
378 status collapsed
379
380 \begin_layout Standard
381 there are short notes, long notes and separate notes
382 \end_layout
383
384 \end_inset
385
386 There are also short notes we can attach to every variable in the model.
387 A "one liner
388 \begin_inset LatexCommand \index{notes, one liner}
389
390 \end_inset
391
392
393 \begin_inset LatexCommand \index{one liner}
394
395 \end_inset
396
397 " in double quotes just following the variable name allows the automatic
398 annotation of variables in reports.
399 \end_layout
400
401 \begin_layout Standard
402 The last few lines of Figure
403 \begin_inset LatexCommand \ref{fig:model2.vesselWithNotes}
404
405 \end_inset
406
407
408 \noun off
409 shows adding notes we write in a separate ADD NOTES IN object
410 \begin_inset LatexCommand \index{ADD NOTES IN object}
411
412 \end_inset
413
414 .
415 This object can appear before or after or in a different file from the
416 object it describes.
417 This style of note writing is useful as it allows another person to add
418 notes to a model without changing the code for a model.
419 Thus it allows several different sets of notes to exist for a single model,
420 with the choice of which to use being up to the person maintaining the
421 model library.
422 Finally, it allows one to eliminate the "clutter" the documentation often
423 adds to the code.
424 \end_layout
425
426 \begin_layout Section
427 Adding methods
428 \begin_inset LatexCommand \index{methods, adding}
429
430 \end_inset
431
432
433 \begin_inset LatexCommand \index{adding methods}
434
435 \end_inset
436
437
438 \end_layout
439
440 \begin_layout Standard
441 We would next like to pass along our experiences in getting this model to
442 be well-posed -- i.e., we would like to tell future users which variables
443 we decided to fix and which we decided to calculate.
444 We would also like to provide some typical values for the variables we
445 decided to fix.
446 ASCEND allows us to attach any number of methods to a type definition.
447 Methods are procedural code that we can request be run through the interface
448 while browsing a model instance.
449 We shall include methods as described in Table
450 \begin_inset LatexCommand \ref{tab:model2.reqdMethods}
451
452 \end_inset
453
454
455 \noun off
456 to set just the right fixed flags and variable values for an instance of
457 our vessel model to be well-posed.
458 \end_layout
459
460 \begin_layout Standard
461 The system has defaults definitions for all these methods.
462 You already saw that to be true if you went through the process of setting
463 all the fixed flags to FALSE in the previous chapter.
464 In case you did not, load and compile the vesselPlain.a4c model in ASCEND.
465 Export the compiled instance to the Browser.
466 Then in the Browser, under the Edit button, select Run method.
467 You will see a list containing these and other methods we shall be describing
468 shortly.
469 Select specify and hit the OK button.
470 Then look in the Console window.
471 A message similar to the following will appear, with all but the first
472 line being in red to signify you should pay attention to the message:
473 \end_layout
474
475 \begin_layout LyX-Code
476 Running method specify in v
477 \end_layout
478
479 \begin_layout LyX-Code
480 Found STOP
481 \begin_inset LatexCommand \index{STOP}
482
483 \end_inset
484
485 statement in METHOD
486 \end_layout
487
488 \begin_layout LyX-Code
489 C:
490 \backslash
491 PROGRAM FILES
492 \backslash
493 ASCEND
494 \backslash
495 ASCEND4
496 \backslash
497 models
498 \backslash
499 basemodel.a4l:307
500 \end_layout
501
502 \begin_layout LyX-Code
503 STOP {Error
504 \begin_inset LatexCommand \index{error}
505
506 \end_inset
507
508 ! Standard method "specify" called but not
509 \end_layout
510
511 \begin_layout LyX-Code
512 written in MODEL.};
513 \end_layout
514
515 \begin_layout Standard
516 This message is telling you that you have just run the default specify method
517 \begin_inset LatexCommand \index{specify method, default}
518
519 \end_inset
520
521 .
522 We have to hand-craft every specify method so the default method is not
523 appropriate.
524 This message is alerting us to the fact that we did not yet write a special
525 specify method for this model type.
526 \end_layout
527
528 \begin_layout Standard
529 Try running the ClearAll
530 \begin_inset LatexCommand \index{ClearAll}
531
532 \end_inset
533
534 method.
535 The default ClearAll method is always the one you will want so it does
536 not put out a message to alert you that it is the default.
537
538 \end_layout
539
540 \begin_layout Standard
541 \begin_inset Float table
542 wide false
543 sideways false
544 status open
545
546 \begin_layout Caption
547 \begin_inset LatexCommand \label{tab:model2.reqdMethods}
548
549 \end_inset
550
551 Some of the methods
552 \begin_inset LatexCommand \index{methods, required}
553
554 \end_inset
555
556 we require for putting a model into an ASCEND library
557 \end_layout
558
559 \begin_layout Standard
560 \begin_inset Tabular
561 <lyxtabular version="3" rows="5" columns="2">
562 <features>
563 <column alignment="center" valignment="top" leftline="true" width="1.25in">
564 <column alignment="center" valignment="top" leftline="true" rightline="true" width="3.5in">
565 <row topline="true" bottomline="true">
566 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
567 \begin_inset Text
568
569 \begin_layout Standard
570
571 \end_layout
572
573 \end_inset
574 </cell>
575 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
576 \begin_inset Text
577
578 \begin_layout Standard
579
580 \end_layout
581
582 \end_inset
583 </cell>
584 </row>
585 <row topline="true">
586 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
587 \begin_inset Text
588
589 \begin_layout Standard
590
591 \family typewriter
592 ClearAll
593 \family default
594
595 \begin_inset LatexCommand \index{ClearAll}
596
597 \end_inset
598
599
600 \end_layout
601
602 \end_inset
603 </cell>
604 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
605 \begin_inset Text
606
607 \begin_layout Standard
608 a method to set all the .fixed flags for variables in the type to FALSE.
609 This puts these flags into a known standard state -- i.e., all are FALSE.
610 All models inherit this method from the base model and the need to rewrite
611 it is very, very rare.
612 \end_layout
613
614 \end_inset
615 </cell>
616 </row>
617 <row topline="true">
618 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
619 \begin_inset Text
620
621 \begin_layout Standard
622
623 \family typewriter
624 specify
625 \family default
626
627 \begin_inset LatexCommand \index{specify}
628
629 \end_inset
630
631
632 \end_layout
633
634 \end_inset
635 </cell>
636 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
637 \begin_inset Text
638
639 \begin_layout Standard
640
641 \family roman
642 \series medium
643 \shape up
644 \size normal
645 \emph off
646 \bar no
647 \noun off
648 \color none
649 a method which assumes all the fixed flags are currently FALSE and which
650 then sets a suitable set of fixed flags to TRUE to make an instance of
651 this type of model well-posed.
652 A well-posed model is one that is square (n equations in n unknowns) and
653 solvable.
654 \end_layout
655
656 \end_inset
657 </cell>
658 </row>
659 <row topline="true">
660 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
661 \begin_inset Text
662
663 \begin_layout Standard
664
665 \family typewriter
666 reset
667 \family default
668
669 \begin_inset LatexCommand \index{reset}
670
671 \end_inset
672
673
674 \end_layout
675
676 \end_inset
677 </cell>
678 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
679 \begin_inset Text
680
681 \begin_layout Standard
682
683 \family roman
684 \series medium
685 \shape up
686 \size normal
687 \emph off
688 \bar no
689 \noun off
690 \color none
691 a method which first runs the ClearAll method and then the specify method.
692 We include this method because it is very convenient.
693 We only have to run one method to make any simulation well-posed, no matter
694 how its fixed flags are currently set.
695 All models inherit this method from the base model, as with ClearAll .
696 It should only rarely have to be rewritten for a model.
697 \end_layout
698
699 \end_inset
700 </cell>
701 </row>
702 <row topline="true" bottomline="true">
703 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
704 \begin_inset Text
705
706 \begin_layout Standard
707
708 \family typewriter
709 values
710 \family default
711
712 \begin_inset LatexCommand \index{values}
713
714 \end_inset
715
716
717 \end_layout
718
719 \end_inset
720 </cell>
721 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
722 \begin_inset Text
723
724 \begin_layout Standard
725
726 \family roman
727 \series medium
728 \shape up
729 \size normal
730 \emph off
731 \bar no
732 \noun off
733 \color none
734 a method to establish typical values for the variables we have fixed in
735 an application or test model.
736 We may also supply values for some of the variables we will be computing
737 to aid in solving a model instance of this type.
738 These values reflectiveness that we have tested for a simulation of this
739 type and found to work.
740 \end_layout
741
742 \end_inset
743 </cell>
744 </row>
745 </lyxtabular>
746
747 \end_inset
748
749
750 \end_layout
751
752 \end_inset
753
754
755 \end_layout
756
757 \begin_layout Standard
758 \begin_inset Marginal
759 status collapsed
760
761 \begin_layout Standard
762 writing the specify and values methods
763 \end_layout
764
765 \end_inset
766
767 To write the
768 \family typewriter
769 specify
770 \family default
771 and
772 \family typewriter
773 values
774 \family default
775 methods for our vessel model, we note that we have successfully solved
776 the vessel model in at least two different ways above.
777 Thus both variations are examples of being ‚well-posed.‚ We can choose which
778 variation we shall use when creating the
779 \family typewriter
780 specify
781 \family default
782 method for our vessel type definition.
783 Let us choose the alternative where we fixed
784 \family typewriter
785 vessel_volume
786 \family default
787 ,
788 \family typewriter
789 H_to_D_ratio
790 \family default
791 ,
792 \family typewriter
793 metal_density
794 \family default
795 and
796 \family typewriter
797 wall_thickness
798 \family default
799 and provided them with the values of 250 ft^3, 3, 5000 kg/m^3 and 5 mm
800 respectively to be our ‚standard‚ specification.
801 Default methods
802 \family typewriter
803 ClearAll
804 \family default
805 and
806 \family typewriter
807 reset
808 \family default
809 are appropriate
810 \end_layout
811
812 \begin_layout Standard
813 \begin_inset Marginal
814 status collapsed
815
816 \begin_layout Standard
817 default methods ClearAll and reset are appropriate
818 \end_layout
819
820 \end_inset
821
822 As already noted, the purpose of
823 \family typewriter
824 ClearAll
825 \family default
826 is to set all the fixed flags to FALSE, a well-defined state from which
827 we can start over to set these flags as we wish them set.
828
829 \family typewriter
830 reset
831 \family default
832 simply runs
833 \family typewriter
834 ClearAll
835 \family default
836 and then
837 \family typewriter
838 specify
839 \family default
840 for a model.
841 The default versions for these two methods are generally exactly what one
842 wants so one need not write these.
843 \end_layout
844
845 \begin_layout Standard
846 Figure
847 \begin_inset LatexCommand \ref{fig:model2.vesselWithMethods}
848
849 \end_inset
850
851
852 \noun off
853 illustrates our vessel model with our local versions added for
854 \family typewriter
855 \noun default
856 specify
857 \family default
858 \noun off
859 and
860 \family typewriter
861 \noun default
862 values
863 \family default
864 \noun off
865 .
866 Look only at these for the moment and note that they do what we described
867 above.
868 We show some other methods we shall explain in a moment.
869 \end_layout
870
871 \begin_layout Standard
872 \begin_inset Float figure
873 wide false
874 sideways false
875 status open
876
877 \begin_layout LyX-Code
878 REQUIRE "atoms.a4l";
879 \end_layout
880
881 \begin_layout LyX-Code
882 MODEL vessel;
883 \end_layout
884
885 \begin_layout LyX-Code
886 NOTES
887 \end_layout
888
889 \begin_layout LyX-Code
890 'author' SELF {Arthur W.
891 Westerberg}
892 \end_layout
893
894 \begin_layout LyX-Code
895 'creation date' SELF {May, 1998}
896 \end_layout
897
898 \begin_layout LyX-Code
899 END NOTES;
900 \end_layout
901
902 \begin_layout LyX-Code
903
904 \end_layout
905
906 \begin_layout LyX-Code
907 (* variables *)
908 \end_layout
909
910 \begin_layout LyX-Code
911 side_area "the area of the cylindrical side wall of the vessel",
912 \end_layout
913
914 \begin_layout LyX-Code
915 end_area "the area of the flat ends of the vessel"
916 \end_layout
917
918 \begin_layout LyX-Code
919 IS_A area;
920 \end_layout
921
922 \begin_layout LyX-Code
923 vessel_vol "the volume contained within the cylindrical vessel",
924 \end_layout
925
926 \begin_layout LyX-Code
927 wall_vol "the volume of the walls for the vessel"
928 \end_layout
929
930 \begin_layout LyX-Code
931 IS_A volume;
932 \end_layout
933
934 \begin_layout LyX-Code
935 wall_thickness "the thickness of all of the vessel walls",
936 \end_layout
937
938 \begin_layout LyX-Code
939 H "the vessel height (of the cylindrical side walls)",
940 \end_layout
941
942 \begin_layout LyX-Code
943 D "the vessel diameter"
944 \end_layout
945
946 \begin_layout LyX-Code
947 IS_A distance;
948 \end_layout
949
950 \begin_layout LyX-Code
951 H_to_D_ratio "the ratio of vessel height to diameter"
952 \end_layout
953
954 \begin_layout LyX-Code
955 IS_A factor;
956 \end_layout
957
958 \begin_layout LyX-Code
959 metal_density "density of the metal from which the vessel
960 \end_layout
961
962 \begin_layout LyX-Code
963 is constructed"
964 \end_layout
965
966 \begin_layout LyX-Code
967 IS_A mass_density;
968 \end_layout
969
970 \begin_layout LyX-Code
971 metal_mass "the mass of the metal in the walls of the vessel"
972 \end_layout
973
974 \begin_layout LyX-Code
975 IS_A mass;
976 \end_layout
977
978 \begin_layout LyX-Code
979 (* equations *)
980 \end_layout
981
982 \begin_layout LyX-Code
983 FlatEnds:end_area = 1{PI} * D^2 / 4;
984 \end_layout
985
986 \begin_layout LyX-Code
987 Sides:side_area = 1{PI} * D * H;
988 \end_layout
989
990 \begin_layout LyX-Code
991 Cylinder:vessel_vol = end_area * H;
992 \end_layout
993
994 \begin_layout LyX-Code
995 Metal_volume:(side_area + 2 * end_area) * wall_thickness = wall_vol;
996 \end_layout
997
998 \begin_layout LyX-Code
999 HD_definition:D * H_to_D_ratio = H;
1000 \end_layout
1001
1002 \begin_layout LyX-Code
1003 VesselMass:metal_mass = metal_density * wall_vol;
1004 \end_layout
1005
1006 \begin_layout LyX-Code
1007
1008 \end_layout
1009
1010 \begin_layout LyX-Code
1011 METHODS
1012 \end_layout
1013
1014 \begin_layout LyX-Code
1015 METHOD specify;
1016 \end_layout
1017
1018 \begin_layout LyX-Code
1019 NOTES
1020 \end_layout
1021
1022 \begin_layout LyX-Code
1023 'purpose' SELF {to fix four variables and make the problem well-posed}
1024 \end_layout
1025
1026 \begin_layout LyX-Code
1027 END NOTES;
1028 \end_layout
1029
1030 \begin_layout LyX-Code
1031 vessel_vol.fixed:=TRUE;
1032 \end_layout
1033
1034 \begin_layout LyX-Code
1035 H_to_D_ratio.fixed:=TRUE;
1036 \end_layout
1037
1038 \begin_layout LyX-Code
1039 wall_thickness.fixed :=TRUE;
1040 \end_layout
1041
1042 \begin_layout LyX-Code
1043 metal_density.fixed:=TRUE;
1044 \end_layout
1045
1046 \begin_layout LyX-Code
1047 END specify;
1048 \end_layout
1049
1050 \begin_layout LyX-Code
1051 METHOD values;
1052 \end_layout
1053
1054 \begin_layout LyX-Code
1055 NOTES
1056 \end_layout
1057
1058 \begin_layout LyX-Code
1059 'purpose' SELF {to set the values for the fixed variables}
1060 \end_layout
1061
1062 \begin_layout LyX-Code
1063 END NOTES;
1064 \end_layout
1065
1066 \begin_layout LyX-Code
1067 H_to_D_ratio := 2;
1068 \end_layout
1069
1070 \begin_layout LyX-Code
1071 vessel_vol := 250 {ft^3};
1072 \end_layout
1073
1074 \begin_layout LyX-Code
1075 wall_thickness := 5 {mm};
1076 \end_layout
1077
1078 \begin_layout LyX-Code
1079 metal_density := 5000 {kg/m^3};
1080 \end_layout
1081
1082 \begin_layout LyX-Code
1083 END values;
1084 \end_layout
1085
1086 \begin_layout LyX-Code
1087 METHOD bound_self;
1088 \end_layout
1089
1090 \begin_layout LyX-Code
1091 END bound_self;
1092 \end_layout
1093
1094 \begin_layout LyX-Code
1095 METHOD scale_self;
1096 \end_layout
1097
1098 \begin_layout LyX-Code
1099 END scale_self;
1100 \end_layout
1101
1102 \begin_layout LyX-Code
1103 METHOD default_self;
1104 \end_layout
1105
1106 \begin_layout LyX-Code
1107 D:=1 {m};
1108 \end_layout
1109
1110 \begin_layout LyX-Code
1111 H:=1 {m};
1112 \end_layout
1113
1114 \begin_layout LyX-Code
1115 H_to_D_ratio :=1;
1116 \end_layout
1117
1118 \begin_layout LyX-Code
1119 vessel_vol := 1 {m^3};
1120 \end_layout
1121
1122 \begin_layout LyX-Code
1123 wall_thickness :=5 {mm};
1124 \end_layout
1125
1126 \begin_layout LyX-Code
1127 metal_density :=5000 {kg/m^3};
1128 \end_layout
1129
1130 \begin_layout LyX-Code
1131 END default_self;
1132 \end_layout
1133
1134 \begin_layout LyX-Code
1135 END vessel;
1136 \end_layout
1137
1138 \begin_layout LyX-Code
1139
1140 \end_layout
1141
1142 \begin_layout LyX-Code
1143 ADD NOTES IN vessel;
1144 \end_layout
1145
1146 \begin_layout LyX-Code
1147 'description' SELF {This model relates the dimensions of a
1148 \end_layout
1149
1150 \begin_layout LyX-Code
1151 cylindrical vessel -- e.g., diameter, height and wall thickness
1152 \end_layout
1153
1154 \begin_layout LyX-Code
1155 to the volume of metal in the walls.
1156 It uses a thin wall
1157 \end_layout
1158
1159 \begin_layout LyX-Code
1160 assumption -- i.e., that the volume of metal is the area of
1161 \end_layout
1162
1163 \begin_layout LyX-Code
1164 the vessel times the wall thickness.}
1165 \end_layout
1166
1167 \begin_layout LyX-Code
1168 'purpose' SELF {to illustrate the insertion of notes into a model}
1169 \end_layout
1170
1171 \begin_layout LyX-Code
1172 END NOTES;
1173 \end_layout
1174
1175 \begin_layout Caption
1176 Version of vessel with methods added (vesselMethods.a4c
1177 \begin_inset LatexCommand \index{vesselMethods.a4c}
1178
1179 \end_inset
1180
1181 )
1182 \begin_inset LatexCommand \label{fig:model2.vesselWithMethods}
1183
1184 \end_inset
1185
1186
1187 \end_layout
1188
1189 \end_inset
1190
1191
1192 \end_layout
1193
1194 \begin_layout Standard
1195 In Table
1196 \begin_inset LatexCommand \ref{tab:model2.addedReqdMethods}
1197
1198 \end_inset
1199
1200
1201 \noun off
1202 we describe additional methods we require before we will put a model into
1203 one of our libraries.
1204 Each of these had two versions, both of which we require.
1205 The designation _self
1206 \begin_inset LatexCommand \index{\_self}
1207
1208 \end_inset
1209
1210 is for a method to do something for all the variables and/or parts we have
1211 defined locally within the current model with an IS_A statement.
1212 The designation _all
1213 \begin_inset LatexCommand \index{\_all}
1214
1215 \end_inset
1216
1217 is for a method to do something for parts that are defined within an "outer"
1218 model that has an instance of this model as a part.
1219 The "outer" model is at a higher scope
1220 \begin_inset LatexCommand \index{scope}
1221
1222 \end_inset
1223
1224 .
1225 It can share its parts with this model by passing them in as parameters,
1226 a topic we cover shortly in
1227 \noun default
1228 Section
1229 \noun off
1230
1231 \begin_inset LatexCommand \ref{sec:model2.parameterizingVessel}
1232
1233 \end_inset
1234
1235 .
1236
1237 \noun default
1238
1239 \noun off
1240 Only the _self versions of these methods are relevant here and are in
1241 \noun default
1242 Figure
1243 \noun off
1244
1245 \begin_inset LatexCommand \ref{fig:model2.vesselWithMethods}
1246
1247 \end_inset
1248
1249 .
1250 \end_layout
1251
1252 \begin_layout Standard
1253 \begin_inset Float table
1254 wide false
1255 sideways false
1256 status open
1257
1258 \begin_layout Caption
1259 Additional methods
1260 \begin_inset LatexCommand \index{methods. required}
1261
1262 \end_inset
1263
1264 required for model in ASCEND libraries
1265 \begin_inset LatexCommand \label{tab:model2.addedReqdMethods}
1266
1267 \end_inset
1268
1269
1270 \end_layout
1271
1272 \begin_layout Standard
1273 \begin_inset Tabular
1274 <lyxtabular version="3" rows="5" columns="2">
1275 <features>
1276 <column alignment="center" valignment="top" leftline="true" width="1.25in">
1277 <column alignment="center" valignment="top" leftline="true" rightline="true" width="3.5in">
1278 <row topline="true" bottomline="true">
1279 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1280 \begin_inset Text
1281
1282 \begin_layout Standard
1283 method
1284 \end_layout
1285
1286 \end_inset
1287 </cell>
1288 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1289 \begin_inset Text
1290
1291 \begin_layout Standard
1292 description
1293 \end_layout
1294
1295 \end_inset
1296 </cell>
1297 </row>
1298 <row topline="true">
1299 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1300 \begin_inset Text
1301
1302 \begin_layout Standard
1303
1304 \family typewriter
1305 default_self
1306 \begin_inset LatexCommand \index{default\_self}
1307
1308 \end_inset
1309
1310 , default_all
1311 \family default
1312
1313 \begin_inset LatexCommand \index{default\_all}
1314
1315 \end_inset
1316
1317
1318 \end_layout
1319
1320 \end_inset
1321 </cell>
1322 <cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none" width="3.5in">
1323 \begin_inset Text
1324
1325 \begin_layout Standard
1326
1327 \family roman
1328 \series medium
1329 \shape up
1330 \size normal
1331 \emph off
1332 \bar no
1333 \noun off
1334 \color none
1335 a method called automatically when any simulation is compiled to provide
1336 default values and adjust bounds for any variables which may have unsuitable
1337 defaults in their ATOM definitions.
1338 Usually the variables selected are those for which the model becomes ill-behave
1339 d if given poor initial guesses or bounds (e.g., zero).
1340 \end_layout
1341
1342 \end_inset
1343 </cell>
1344 </row>
1345 <row topline="true">
1346 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1347 \begin_inset Text
1348
1349 \begin_layout Standard
1350
1351 \family typewriter
1352 bound_self
1353 \begin_inset LatexCommand \index{bound\_self}
1354
1355 \end_inset
1356
1357 , bound_all
1358 \family default
1359
1360 \begin_inset LatexCommand \index{bound\_all}
1361
1362 \end_inset
1363
1364
1365 \end_layout
1366
1367 \end_inset
1368 </cell>
1369 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1370 \begin_inset Text
1371
1372 \begin_layout Standard
1373
1374 \family roman
1375 \series medium
1376 \shape up
1377 \size normal
1378 \emph off
1379 \bar no
1380 \noun off
1381 \color none
1382 a method to update the .
1383 upper_bound and .
1384 lower_bound value for each of the variables.
1385 ASCEND solvers use these bound values to help solve the model equations.
1386 \end_layout
1387
1388 \end_inset
1389 </cell>
1390 </row>
1391 <row topline="true">
1392 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1393 \begin_inset Text
1394
1395 \begin_layout Standard
1396
1397 \family typewriter
1398 scale_self
1399 \begin_inset LatexCommand \index{scale\_self}
1400
1401 \end_inset
1402
1403 , scale_all
1404 \family default
1405
1406 \begin_inset LatexCommand \index{scale\_all}
1407
1408 \end_inset
1409
1410
1411 \end_layout
1412
1413 \end_inset
1414 </cell>
1415 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1416 \begin_inset Text
1417
1418 \begin_layout Standard
1419
1420 \family roman
1421 \series medium
1422 \shape up
1423 \size normal
1424 \emph off
1425 \bar no
1426 \noun off
1427 \color none
1428 a method to update the .
1429 nominal value for each of the variables.
1430 ASCEND solvers will use these nominal values to rescale the variable to
1431 have a value of about one in magnitude to help solve the model equations.
1432 \end_layout
1433
1434 \end_inset
1435 </cell>
1436 </row>
1437 <row topline="true" bottomline="true">
1438 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1439 \begin_inset Text
1440
1441 \begin_layout Standard
1442
1443 \family typewriter
1444 check_self
1445 \begin_inset LatexCommand \index{check\_self}
1446
1447 \end_inset
1448
1449 , check_all
1450 \family default
1451
1452 \begin_inset LatexCommand \index{check\_all}
1453
1454 \end_inset
1455
1456
1457 \end_layout
1458
1459 \end_inset
1460 </cell>
1461 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1462 \begin_inset Text
1463
1464 \begin_layout Standard
1465
1466 \family roman
1467 \series medium
1468 \shape up
1469 \size normal
1470 \emph off
1471 \bar no
1472 \noun off
1473 \color none
1474 a method to check that the computations make sense.
1475 At first this method may be empty, but, with experience, one can add statements
1476 that detect answers that appear to be wrong.
1477 As ASCEND already does bounds checking, one should not check for going
1478 past bounds here.
1479 However, there could be a rule of thumb available that suggests one computed
1480 variable should be about an order of magnitude larger than another.
1481 This check could be done in this method.
1482 \end_layout
1483
1484 \end_inset
1485 </cell>
1486 </row>
1487 </lyxtabular>
1488
1489 \end_inset
1490
1491
1492 \end_layout
1493
1494 \end_inset
1495
1496
1497 \end_layout
1498
1499 \begin_layout Standard
1500 \begin_inset Marginal
1501 status collapsed
1502
1503 \begin_layout Standard
1504 standard methods to a model definition
1505 \end_layout
1506
1507 \end_inset
1508
1509 The
1510 \family typewriter
1511 bound_self
1512 \family default
1513 and
1514 \family typewriter
1515 scale_self
1516 \family default
1517 , methods we have written are both empty.
1518 We anticipate no difficulties with variable scaling or bounding for this
1519 small model.
1520 Larger models can often give difficult problems in solving if the variables
1521 in them are not properly scaled and bounded; these issues must be taken
1522 very seriously for such models.
1523 \end_layout
1524
1525 \begin_layout Standard
1526 We have included the variables that define the geometry of the vessel in
1527
1528 \family typewriter
1529 defaults_self
1530 \family default
1531 method to avoid such things as negative initial values for vessel_volume.
1532 The compiler for ASCEND runs this method as soon as the model is compiled
1533 into an instance so the variables mentioned here start with their default
1534 values.
1535 \end_layout
1536
1537 \begin_layout Standard
1538 \begin_inset Marginal
1539 status open
1540
1541 \begin_layout Standard
1542 using methods when solving
1543 \end_layout
1544
1545 \end_inset
1546
1547 Exit ASCEND and repeat all the steps above to edit, load and compile this
1548 new vessel type definition.
1549 Then proceed as follows.
1550 \end_layout
1551
1552 \begin_layout Itemize
1553 In the Browser window, examine the values for those variables mentioned
1554 in the default_self method.
1555 Note they already have their default values.
1556 \end_layout
1557
1558 \begin_layout Itemize
1559 To place the new instance v in a solvable state, go to the Browser window.
1560 Pick the command Run method under the Edit button.
1561 Select first the method values and hit OK.
1562 \end_layout
1563
1564 \begin_layout Itemize
1565 Repeat the last step but this time select the method reset.
1566
1567 \end_layout
1568
1569 \begin_layout Standard
1570 In the Browser, examine the values for the variables listed in the method
1571 values in Figure
1572 \begin_inset LatexCommand \ref{fig:model2.vesselWithMethods}
1573
1574 \end_inset
1575
1576
1577 \noun off
1578 .
1579 They should be set to those stated (remember you can alter the units ASCEND
1580 uses to report the values by using the tools in the Units window).Also examine
1581 the fixed flags for these variables; they should all be TRUE (remember
1582 that you can find which variables are fixed all at once by using the By
1583 type command under the Find button).
1584
1585 \end_layout
1586
1587 \begin_layout Itemize
1588 Finally export v to the Solver.
1589 The Eligible window should NOT appear; rather that Solver should report
1590 the model to be square.
1591
1592 \end_layout
1593
1594 \begin_layout Itemize
1595 Solve by selecting Solve under the Execute button.
1596 \end_layout
1597
1598 \begin_layout Standard
1599 The inclusion of methods has made the process of making this model much
1600 easier to get well-posed.
1601 This approach is the one that works for really large, complex models.
1602 \end_layout
1603
1604 \begin_layout Section
1605 Parameterizing the vessel model
1606 \begin_inset LatexCommand \label{sec:model2.parameterizingVessel}
1607
1608 \end_inset
1609
1610
1611 \end_layout
1612
1613 \begin_layout Standard
1614 \begin_inset Marginal
1615 status collapsed
1616
1617 \begin_layout Standard
1618 let's compute metal_mass vs.
1619 H_to_D_ratio
1620 \end_layout
1621
1622 \end_inset
1623
1624 Reuse generally implies creating a model which will have as a part an instance
1625 of a previously defined type.
1626 For example, let us compute metal_mass as a function of the H_to_D_ratio
1627 for a vessel for a fixed vessel_volume.
1628 We would like to see if there is a value for the H_to_D_ratio for which
1629 the metal_mass is minimum for a vessel with a given vessel_volume.
1630 We might wonder if metal_mass goes to infinity as this ratio goes either
1631 to zero or infinity.
1632 \end_layout
1633
1634 \begin_layout Subsection
1635 Creating a parameterized version of vessel
1636 \end_layout
1637
1638 \begin_layout Standard
1639 \begin_inset Marginal
1640 status collapsed
1641
1642 \begin_layout Standard
1643 parameters indicate likely object sharing
1644 \end_layout
1645
1646 \end_inset
1647
1648 To use instances of our model as parts in another model, we can parameterize
1649 it.
1650 We use parameterization to tell a future user that the parameters are objects
1651 he or she is likely to share among many different parts of a model.
1652 We wish to create a table containing different values of H_to_D_ratio vs.
1653 metal_mass.
1654 We can accomplish this by computing simultaneously several different vessels
1655 having the same vessel_volume, wall_thickness and metal_density.
1656 The objects we want to see and/or share for each instance of a vessel should
1657 include, therefore: H_to_D_ratio, metal_mass, metal_density, vessel_volume
1658 and wall_thickness.
1659 \end_layout
1660
1661 \begin_layout Standard
1662 The code in Figure
1663 \begin_inset LatexCommand \ref{fig:model2.parameterizedVessel}
1664
1665 \end_inset
1666
1667
1668 \noun off
1669 indicates the changes we make to the model declaration statement and the
1670 statements defining the variables to parameterize our model.
1671 \end_layout
1672
1673 \begin_layout Standard
1674 \begin_inset Float figure
1675 wide false
1676 sideways false
1677 status open
1678
1679 \begin_layout LyX-Code
1680 REQUIRE "atoms.a4l";
1681 \end_layout
1682
1683 \begin_layout LyX-Code
1684 MODEL vessel(
1685 \end_layout
1686
1687 \begin_layout LyX-Code
1688 vessel_vol "the volume contained within the cylindrical vessel"
1689 \end_layout
1690
1691 \begin_layout LyX-Code
1692 WILL_BE volume;
1693 \end_layout
1694
1695 \begin_layout LyX-Code
1696 wall_thickness "the thickness of all of the vessel walls"
1697 \end_layout
1698
1699 \begin_layout LyX-Code
1700 WILL_BE distance;
1701 \end_layout
1702
1703 \begin_layout LyX-Code
1704 metal_density "density of the metal from which the vessel
1705 \end_layout
1706
1707 \begin_layout LyX-Code
1708 is constructed"
1709 \end_layout
1710
1711 \begin_layout LyX-Code
1712 WILL_BE mass_density;
1713 \end_layout
1714
1715 \begin_layout LyX-Code
1716 H_to_D_ratio "the ratio of vessel height to diameter"
1717 \end_layout
1718
1719 \begin_layout LyX-Code
1720 WILL_BE factor;
1721 \end_layout
1722
1723 \begin_layout LyX-Code
1724 metal_mass "the mass of the metal in the walls of the vessel"
1725 \end_layout
1726
1727 \begin_layout LyX-Code
1728 WILL_BE mass;
1729 \end_layout
1730
1731 \begin_layout LyX-Code
1732 );
1733 \end_layout
1734
1735 \begin_layout LyX-Code
1736 NOTES
1737 \end_layout
1738
1739 \begin_layout LyX-Code
1740 'author' SELF {Arthur W.
1741 Westerberg}
1742 \end_layout
1743
1744 \begin_layout LyX-Code
1745 'creation date' SELF {May, 1998}
1746 \end_layout
1747
1748 \begin_layout LyX-Code
1749 END NOTES;
1750 \end_layout
1751
1752 \begin_layout LyX-Code
1753
1754 \end_layout
1755
1756 \begin_layout LyX-Code
1757 (* variables *)
1758 \end_layout
1759
1760 \begin_layout LyX-Code
1761 side_area "the area of the cylindrical side wall of the vessel",
1762 \end_layout
1763
1764 \begin_layout LyX-Code
1765 end_area "the area of the flat ends of the vessel"
1766 \end_layout
1767
1768 \begin_layout LyX-Code
1769 IS_A area;
1770 \end_layout
1771
1772 \begin_layout LyX-Code
1773 wall_vol "the volume of the walls for the vessel"
1774 \end_layout
1775
1776 \begin_layout LyX-Code
1777 IS_A volume;
1778 \end_layout
1779
1780 \begin_layout LyX-Code
1781 H "the vessel height (of the cylindrical side walls)",
1782 \end_layout
1783
1784 \begin_layout LyX-Code
1785 D "the vessel diameter"
1786 \end_layout
1787
1788 \begin_layout LyX-Code
1789 IS_A distance;
1790 \end_layout
1791
1792 \begin_layout LyX-Code
1793 (* equations *)
1794 \end_layout
1795
1796 \begin_layout LyX-Code
1797 FlatEnds:end_area = 1{PI} * D^2 / 4;
1798 \end_layout
1799
1800 \begin_layout LyX-Code
1801 Sides:side_area = 1{PI} * D * H;
1802 \end_layout
1803
1804 \begin_layout LyX-Code
1805 Cylinder:vessel_vol = end_area * H;
1806 \end_layout
1807
1808 \begin_layout LyX-Code
1809 Metal_volume:(side_area + 2 * end_area) * wall_thickness = wall_vol;
1810 \end_layout
1811
1812 \begin_layout LyX-Code
1813 HD_definition:D * H_to_D_ratio = H;
1814 \end_layout
1815
1816 \begin_layout LyX-Code
1817 VesselMass:metal_mass = metal_density * wall_vol;
1818 \end_layout
1819
1820 \begin_layout LyX-Code
1821
1822 \end_layout
1823
1824 \begin_layout LyX-Code
1825 METHODS
1826 \end_layout
1827
1828 \begin_layout LyX-Code
1829 METHOD specify;
1830 \end_layout
1831
1832 \begin_layout LyX-Code
1833 NOTES
1834 \end_layout
1835
1836 \begin_layout LyX-Code
1837 'purpose' SELF {to fix four variables and make the problem well-posed}
1838 \end_layout
1839
1840 \begin_layout LyX-Code
1841 END NOTES;
1842 \end_layout
1843
1844 \begin_layout LyX-Code
1845 vessel_vol.fixed:=TRUE;
1846 \end_layout
1847
1848 \begin_layout LyX-Code
1849 H_to_D_ratio.fixed:=TRUE;
1850 \end_layout
1851
1852 \begin_layout LyX-Code
1853 wall_thickness.fixed :=TRUE;
1854 \end_layout
1855
1856 \begin_layout LyX-Code
1857 metal_density.fixed:=TRUE;
1858 \end_layout
1859
1860 \begin_layout LyX-Code
1861 END specify;
1862 \end_layout
1863
1864 \begin_layout LyX-Code
1865 METHOD values;
1866 \end_layout
1867
1868 \begin_layout LyX-Code
1869 NOTES
1870 \end_layout
1871
1872 \begin_layout LyX-Code
1873 'purpose' SELF {to set the values for the fixed variables}
1874 \end_layout
1875
1876 \begin_layout LyX-Code
1877 END NOTES;
1878 \end_layout
1879
1880 \begin_layout LyX-Code
1881 H_to_D_ratio:=2;
1882 \end_layout
1883
1884 \begin_layout LyX-Code
1885 vessel_vol:=250 {ft^3};
1886 \end_layout
1887
1888 \begin_layout LyX-Code
1889 wall_thickness:=5 {mm};
1890 \end_layout
1891
1892 \begin_layout LyX-Code
1893 metal_density:=5000 {kg/m^3};
1894 \end_layout
1895
1896 \begin_layout LyX-Code
1897 END values;
1898 \end_layout
1899
1900 \begin_layout LyX-Code
1901 METHOD bound_self;
1902 \end_layout
1903
1904 \begin_layout LyX-Code
1905 END bound_self;
1906 \end_layout
1907
1908 \begin_layout LyX-Code
1909 METHOD bound_all;
1910 \end_layout
1911
1912 \begin_layout LyX-Code
1913 RUN bound_self;
1914 \end_layout
1915
1916 \begin_layout LyX-Code
1917 END bound_all;
1918 \end_layout
1919
1920 \begin_layout LyX-Code
1921 METHOD scale_self;
1922 \end_layout
1923
1924 \begin_layout LyX-Code
1925 END scale_self;
1926 \end_layout
1927
1928 \begin_layout LyX-Code
1929 METHOD scale_all;
1930 \end_layout
1931
1932 \begin_layout LyX-Code
1933 RUN scale_self;
1934 \end_layout
1935
1936 \begin_layout LyX-Code
1937 END scale_all;
1938 \end_layout
1939
1940 \begin_layout LyX-Code
1941 METHOD default_self;
1942 \end_layout
1943
1944 \begin_layout LyX-Code
1945 D:=1 {m};
1946 \end_layout
1947
1948 \begin_layout LyX-Code
1949 H:=1 {m};
1950 \end_layout
1951
1952 \begin_layout LyX-Code
1953 END default_self;
1954 \end_layout
1955
1956 \begin_layout LyX-Code
1957 METHOD default_all;
1958 \end_layout
1959
1960 \begin_layout LyX-Code
1961 RUN default_self;
1962 \end_layout
1963
1964 \begin_layout LyX-Code
1965 vessel_vol:=1 {m^3};
1966 \end_layout
1967
1968 \begin_layout LyX-Code
1969 wall_thickness:=5 {mm};
1970 \end_layout
1971
1972 \begin_layout LyX-Code
1973 metal_density:=5000 {kg/m^3};
1974 \end_layout
1975
1976 \begin_layout LyX-Code
1977 H_to_D_ratio:=1;
1978 \end_layout
1979
1980 \begin_layout LyX-Code
1981 END default_all;
1982 \end_layout
1983
1984 \begin_layout LyX-Code
1985 END vessel;
1986 \end_layout
1987
1988 \begin_layout LyX-Code
1989 ADD NOTES IN vessel;
1990 \end_layout
1991
1992 \begin_layout LyX-Code
1993 'description' SELF {This model relates the dimensions of a
1994 \end_layout
1995
1996 \begin_layout LyX-Code
1997 cylindrical vessel -- e.g., diameter, height and wall thickness
1998 \end_layout
1999
2000 \begin_layout LyX-Code
2001 to the volume of metal in the walls.
2002 It uses a thin wall
2003 \end_layout
2004
2005 \begin_layout LyX-Code
2006 assumption -- i.e., that the volume of metal is the area of
2007 \end_layout
2008
2009 \begin_layout LyX-Code
2010 the vessel times the wall thickness.}
2011 \end_layout
2012
2013 \begin_layout LyX-Code
2014 'purpose' SELF {to illustrate the insertion of notes into a model}
2015 \end_layout
2016
2017 \begin_layout LyX-Code
2018 END NOTES;
2019 \end_layout
2020
2021 \begin_layout Caption
2022 \begin_inset LatexCommand \label{fig:model2.parameterizedVessel}
2023
2024 \end_inset
2025
2026 The parameterized version of vessel model (
2027 \begin_inset LatexCommand \index{1014608}
2028
2029 \end_inset
2030
2031 vesselParams.a4c)sss
2032 \end_layout
2033
2034 \end_inset
2035
2036
2037 \end_layout
2038
2039 \begin_layout Standard
2040 Substitute the statements in Figure
2041 \begin_inset LatexCommand \ref{fig:model2.parameterizedVessel}
2042
2043 \end_inset
2044
2045
2046 \noun off
2047 for lines 2 through 9 in
2048 \noun default
2049 Figure
2050 \noun off
2051
2052 \begin_inset LatexCommand \ref{fig:model2.vesselWithMethods}
2053
2054 \end_inset
2055
2056 .
2057 Save the result in the file vesselParam.a4c.
2058 \end_layout
2059
2060 \begin_layout Standard
2061 Note the use of the
2062 \begin_inset LatexCommand \index{1014610}
2063
2064 \end_inset
2065
2066
2067 \begin_inset LatexCommand \index{1014609}
2068
2069 \end_inset
2070
2071 WILL_BE statement in the parameter list.
2072 By declaring that the type of a parameter will be compatible with the types
2073 shown, the compiler can tell immediately if a user of this model is passing
2074 the wrong type of object when defining an instance of a vessel.
2075 \end_layout
2076
2077 \begin_layout Subsection
2078 Using the parameterized vessel model
2079 \end_layout
2080
2081 \begin_layout Standard
2082 \begin_inset Marginal
2083 status collapsed
2084
2085 \begin_layout Standard
2086 Creating a
2087 \begin_inset LatexCommand \index{1014611}
2088
2089 \end_inset
2090
2091 table of metal_mass values vs.
2092 H_to_D_ratio
2093 \end_layout
2094
2095 \end_inset
2096
2097 A type definition will set up our table of H_to_D_ratio values vs.
2098 metal_mass so we can observe approximately where it attains a minimum value.
2099 ASCEND allows us to create arrays of instances of any type.
2100 Here we shall create an array of vessels.
2101 The type definition is shown in Figure
2102 \begin_inset LatexCommand \ref{fig:model2.tabulatedVessel}
2103
2104 \end_inset
2105
2106
2107 \noun off
2108 .
2109 Note that the line numbers are not a part of the actual code.
2110 We include them here only so we can reference them as needed later.
2111 \end_layout
2112
2113 \begin_layout Standard
2114 \begin_inset Float figure
2115 wide false
2116 sideways false
2117 status open
2118
2119 \begin_layout LyX-Code
2120 REQUIRE "atoms.a4l";
2121 \end_layout
2122
2123 \begin_layout LyX-Code
2124 MODEL vessel(
2125 \end_layout
2126
2127 \begin_layout LyX-Code
2128 vessel_vol "the volume contained within the cylindrical vessel"
2129 \end_layout
2130
2131 \begin_layout LyX-Code
2132 WILL_BE volume;
2133 \end_layout
2134
2135 \begin_layout LyX-Code
2136 wall_thickness "the thickness of all of the vessel walls"
2137 \end_layout
2138
2139 \begin_layout LyX-Code
2140 WILL_BE distance;
2141 \end_layout
2142
2143 \begin_layout LyX-Code
2144 metal_density "density of the metal from which the vessel
2145 \end_layout
2146
2147 \begin_layout LyX-Code
2148 is constructed"
2149 \end_layout
2150
2151 \begin_layout LyX-Code
2152 WILL_BE mass_density;
2153 \end_layout
2154
2155 \begin_layout LyX-Code
2156 H_to_D_ratio "the ratio of vessel height to diameter"
2157 \end_layout
2158
2159 \begin_layout LyX-Code
2160 WILL_BE factor;
2161 \end_layout
2162
2163 \begin_layout LyX-Code
2164 metal_mass "the mass of the metal in the walls of the vessel"
2165 \end_layout
2166
2167 \begin_layout LyX-Code
2168 WILL_BE mass;
2169 \end_layout
2170
2171 \begin_layout LyX-Code
2172 );
2173 \end_layout
2174
2175 \begin_layout LyX-Code
2176 NOTES
2177 \end_layout
2178
2179 \begin_layout LyX-Code
2180 'author' SELF {Arthur W.
2181 Westerberg}
2182 \end_layout
2183
2184 \begin_layout LyX-Code
2185 'creation date' SELF {May, 1998}
2186 \end_layout
2187
2188 \begin_layout LyX-Code
2189 END NOTES;
2190 \end_layout
2191
2192 \begin_layout LyX-Code
2193
2194 \end_layout
2195
2196 \begin_layout LyX-Code
2197 (* variables *)
2198 \end_layout
2199
2200 \begin_layout LyX-Code
2201 side_area "the area of the cylindrical side wall of the vessel",
2202 \end_layout
2203
2204 \begin_layout LyX-Code
2205 end_area "the area of the flat ends of the vessel"
2206 \end_layout
2207
2208 \begin_layout LyX-Code
2209 IS_A area;
2210 \end_layout
2211
2212 \begin_layout LyX-Code
2213 wall_vol "the volume of the walls for the vessel"
2214 \end_layout
2215
2216 \begin_layout LyX-Code
2217 IS_A volume;
2218 \end_layout
2219
2220 \begin_layout LyX-Code
2221 H "the vessel height (of the cylindrical side walls)",
2222 \end_layout
2223
2224 \begin_layout LyX-Code
2225 D "the vessel diameter"
2226 \end_layout
2227
2228 \begin_layout LyX-Code
2229 IS_A distance;
2230 \end_layout
2231
2232 \begin_layout LyX-Code
2233 (* equations *)
2234 \end_layout
2235
2236 \begin_layout LyX-Code
2237 FlatEnds:end_area = 1{PI} * D^2 / 4;
2238 \end_layout
2239
2240 \begin_layout LyX-Code
2241 Sides:side_area = 1{PI} * D * H;
2242 \end_layout
2243
2244 \begin_layout LyX-Code
2245 Cylinder:vessel_vol = end_area * H;
2246 \end_layout
2247
2248 \begin_layout LyX-Code
2249 Metal_volume:(side_area + 2 * end_area) * wall_thickness = wall_vol;
2250 \end_layout
2251
2252 \begin_layout LyX-Code
2253 HD_definition:D * H_to_D_ratio = H;
2254 \end_layout
2255
2256 \begin_layout LyX-Code
2257 VesselMass:metal_mass = metal_density * wall_vol;
2258 \end_layout
2259
2260 \begin_layout LyX-Code
2261 METHODS
2262 \end_layout
2263
2264 \begin_layout LyX-Code
2265 METHOD specify;
2266 \end_layout
2267
2268 \begin_layout LyX-Code
2269 NOTES
2270 \end_layout
2271
2272 \begin_layout LyX-Code
2273 'purpose' SELF {to fix four variables and make the problem well-posed}
2274 \end_layout
2275
2276 \begin_layout LyX-Code
2277 END NOTES;
2278 \end_layout
2279
2280 \begin_layout LyX-Code
2281 vessel_vol.fixed:=TRUE;
2282 \end_layout
2283
2284 \begin_layout LyX-Code
2285 H_to_D_ratio.fixed:=TRUE;
2286 \end_layout
2287
2288 \begin_layout LyX-Code
2289 wall_thickness.fixed:=TRUE;
2290 \end_layout
2291
2292 \begin_layout LyX-Code
2293 metal_density.fixed:=TRUE;
2294 \end_layout
2295
2296 \begin_layout LyX-Code
2297 END specify;
2298 \end_layout
2299
2300 \begin_layout LyX-Code
2301 METHOD values;
2302 \end_layout
2303
2304 \begin_layout LyX-Code
2305 NOTES
2306 \end_layout
2307
2308 \begin_layout LyX-Code
2309 'purpose' SELF {to set the values for the fixed variables}
2310 \end_layout
2311
2312 \begin_layout LyX-Code
2313 END NOTES;
2314 \end_layout
2315
2316 \begin_layout LyX-Code
2317 H_to_D_ratio:=2;
2318 \end_layout
2319
2320 \begin_layout LyX-Code
2321 vessel_vol:=250 {ft^3};
2322 \end_layout
2323
2324 \begin_layout LyX-Code
2325 wall_thickness:=5 {mm};
2326 \end_layout
2327
2328 \begin_layout LyX-Code
2329 metal_density:=5000 {kg/m^3};
2330 \end_layout
2331
2332 \begin_layout LyX-Code
2333 END values;
2334 \end_layout
2335
2336 \begin_layout LyX-Code
2337 METHOD bound_self;
2338 \end_layout
2339
2340 \begin_layout LyX-Code
2341 END bound_self;
2342 \end_layout
2343
2344 \begin_layout LyX-Code
2345 METHOD bound_all;
2346 \end_layout
2347
2348 \begin_layout LyX-Code
2349 RUN bound_self;
2350 \end_layout
2351
2352 \begin_layout LyX-Code
2353 END bound_all;
2354 \end_layout
2355
2356 \begin_layout LyX-Code
2357 METHOD scale_self;
2358 \end_layout
2359
2360 \begin_layout LyX-Code
2361 END scale_self;
2362 \end_layout
2363
2364 \begin_layout LyX-Code
2365 METHOD scale_all;
2366 \end_layout
2367
2368 \begin_layout LyX-Code
2369 RUN scale_self;
2370 \end_layout
2371
2372 \begin_layout LyX-Code
2373 END scale_all;
2374 \end_layout
2375
2376 \begin_layout LyX-Code
2377 METHOD default_self;
2378 \end_layout
2379
2380 \begin_layout LyX-Code
2381 D:= 1 {m};
2382 \end_layout
2383
2384 \begin_layout LyX-Code
2385 H:=1 {m};
2386 \end_layout
2387
2388 \begin_layout LyX-Code
2389 END default_self;
2390 \end_layout
2391
2392 \begin_layout LyX-Code
2393 METHOD default_all;
2394 \end_layout
2395
2396 \begin_layout LyX-Code
2397 RUN default_self;
2398 \end_layout
2399
2400 \begin_layout LyX-Code
2401 vessel_vol:=1 {m^3};
2402 \end_layout
2403
2404 \begin_layout LyX-Code
2405 wall_thickness:=5 {mm};
2406 \end_layout
2407
2408 \begin_layout LyX-Code
2409 metal_density:=5000 {kg/m^3};
2410 \end_layout
2411
2412 \begin_layout LyX-Code
2413 H_to_D_ratio:=1;
2414 \end_layout
2415
2416 \begin_layout LyX-Code
2417 END default_all;
2418 \end_layout
2419
2420 \begin_layout LyX-Code
2421 END vessel;
2422 \end_layout
2423
2424 \begin_layout LyX-Code
2425
2426 \end_layout
2427
2428 \begin_layout LyX-Code
2429 ADD NOTES IN vessel;
2430 \end_layout
2431
2432 \begin_layout LyX-Code
2433 'description' SELF {This model relates the dimensions of a
2434 \end_layout
2435
2436 \begin_layout LyX-Code
2437 cylindrical vessel -- e.g., diameter, height and wall thickness
2438 \end_layout
2439
2440 \begin_layout LyX-Code
2441 to the volume of metal in the walls.
2442 It uses a thin wall
2443 \end_layout
2444
2445 \begin_layout LyX-Code
2446 assumption -- i.e., that the volume of metal is the area of
2447 \end_layout
2448
2449 \begin_layout LyX-Code
2450 the vessel times the wall thickness.}
2451 \end_layout
2452
2453 \begin_layout LyX-Code
2454 'purpose' SELF {to illustrate the insertion of notes into a model}
2455 \end_layout
2456
2457 \begin_layout LyX-Code
2458 END NOTES;
2459 \end_layout
2460
2461 \begin_layout LyX-Code
2462
2463 \end_layout
2464
2465 \begin_layout LyX-Code
2466 MODEL tabulated_vessel_values;
2467 \end_layout
2468
2469 \begin_layout LyX-Code
2470 vessel_volume "volume of all the tabulated vessels"
2471 \end_layout
2472
2473 \begin_layout LyX-Code
2474 IS_A volume;
2475 \end_layout
2476
2477 \begin_layout LyX-Code
2478 wall_thickness "thickness of all the walls for all the vessels"
2479 \end_layout
2480
2481 \begin_layout LyX-Code
2482 IS_A distance;
2483 \end_layout
2484
2485 \begin_layout LyX-Code
2486 metal_density "density of metal used for all vessels"
2487 \end_layout
2488
2489 \begin_layout LyX-Code
2490 IS_A mass_density;
2491 \end_layout
2492
2493 \begin_layout LyX-Code
2494 n_entries "number of vessels to simulate"
2495 \end_layout
2496
2497 \begin_layout LyX-Code
2498 IS_A integer_constant;
2499 \end_layout
2500
2501 \begin_layout LyX-Code
2502 n_entries :== 20;
2503 \end_layout
2504
2505 \begin_layout LyX-Code
2506 H_to_D_ratio[1..n_entries]"set of H to D ratios for which we are
2507 \end_layout
2508
2509 \begin_layout LyX-Code
2510 computing metal mass"
2511 \end_layout
2512
2513 \begin_layout LyX-Code
2514 IS_A factor;
2515 \end_layout
2516
2517 \begin_layout LyX-Code
2518 metal_mass[1..n_entries]"mass of metal in walls of vessels"
2519 \end_layout
2520
2521 \begin_layout LyX-Code
2522 IS_A mass;
2523 \end_layout
2524
2525 \begin_layout LyX-Code
2526 FOR i IN [1..n_entries] CREATE
2527 \end_layout
2528
2529 \begin_layout LyX-Code
2530 v[i] "the i-th vessel model"
2531 \end_layout
2532
2533 \begin_layout LyX-Code
2534 IS_A vessel(vessel_volume, wall_thickness,
2535 \end_layout
2536
2537 \begin_layout LyX-Code
2538 metal_density, H_to_D_ratio[i], metal_mass[i]);
2539 \end_layout
2540
2541 \begin_layout LyX-Code
2542 END FOR;
2543 \end_layout
2544
2545 \begin_layout LyX-Code
2546
2547 \end_layout
2548
2549 \begin_layout LyX-Code
2550 METHODS
2551 \end_layout
2552
2553 \begin_layout LyX-Code
2554 METHOD default_self;
2555 \end_layout
2556
2557 \begin_layout LyX-Code
2558 END default_self;
2559 \end_layout
2560
2561 \begin_layout LyX-Code
2562
2563 \end_layout
2564
2565 \begin_layout LyX-Code
2566 METHOD specify;
2567 \end_layout
2568
2569 \begin_layout LyX-Code
2570 RUN v[1..n_entries].specify;
2571 \end_layout
2572
2573 \begin_layout LyX-Code
2574 END specify;
2575 \end_layout
2576
2577 \begin_layout LyX-Code
2578 METHOD values;
2579 \end_layout
2580
2581 \begin_layout LyX-Code
2582 NOTES 'purpose' SELF {to set up 20 vessel models having H to D ratios
2583 \end_layout
2584
2585 \begin_layout LyX-Code
2586 ranging from 0.1 to 2.}
2587 \end_layout
2588
2589 \begin_layout LyX-Code
2590 END NOTES;
2591 \end_layout
2592
2593 \begin_layout LyX-Code
2594 vessel_volume := 250 {ft^3};
2595 \end_layout
2596
2597 \begin_layout LyX-Code
2598 wall_thickness := 5 {mm};
2599 \end_layout
2600
2601 \begin_layout LyX-Code
2602 metal_density := 5000 {kg/m^3};
2603 \end_layout
2604
2605 \begin_layout LyX-Code
2606 FOR i IN [1..n_entries] DO
2607 \end_layout
2608
2609 \begin_layout LyX-Code
2610 H_to_D_ratio[i] := i/10.0;
2611 \end_layout
2612
2613 \begin_layout LyX-Code
2614 END FOR;
2615 \end_layout
2616
2617 \begin_layout LyX-Code
2618 END values;
2619 \end_layout
2620
2621 \begin_layout LyX-Code
2622 METHOD scale_self;
2623 \end_layout
2624
2625 \begin_layout LyX-Code
2626 END scale_self;
2627 \end_layout
2628
2629 \begin_layout LyX-Code
2630 END tabulated_vessel_values;
2631 \end_layout
2632
2633 \begin_layout LyX-Code
2634
2635 \end_layout
2636
2637 \begin_layout LyX-Code
2638 ADD NOTES IN tabulated_vessel_values;
2639 \end_layout
2640
2641 \begin_layout LyX-Code
2642 'description' SELF {This model sets up an array of vessels to
2643 \end_layout
2644
2645 \begin_layout LyX-Code
2646 compute a range of metal_mass values for different values
2647 \end_layout
2648
2649 \begin_layout LyX-Code
2650 of H_to_D_ratio.}
2651 \end_layout
2652
2653 \begin_layout LyX-Code
2654 'purpose' SELF {to illustrate the use of arrays in ASCEND}
2655 \end_layout
2656
2657 \begin_layout LyX-Code
2658 END NOTES;
2659 \end_layout
2660
2661 \begin_layout Caption
2662 tabulated_vessel_values model
2663 \begin_inset LatexCommand \label{fig:model2.tabulatedVessel}
2664
2665 \end_inset
2666
2667
2668 \end_layout
2669
2670 \end_inset
2671
2672
2673 \end_layout
2674
2675 \begin_layout Standard
2676 Add this model to the end of the file
2677 \family typewriter
2678 vesselParam.a4c
2679 \family default
2680
2681 \begin_inset LatexCommand \index{vesselTabulated.a4c}
2682
2683 \end_inset
2684
2685 (after the vessel model) and save the file as
2686 \family typewriter
2687 vesselTabulated.a4c
2688 \family default
2689 .
2690 Compile an instance of tabulated_vessel_values (call it tvv), run the values
2691 and specify methods for it, and then solve it.
2692 You will discover that the tenth element of the metal_mass array, corresponding
2693 to an
2694 \family typewriter
2695 H_to_D_ratio
2696 \family default
2697 of 1 has the minimum value of 510.257 kilograms.
2698 \end_layout
2699
2700 \begin_layout Section
2701 Creating a script
2702 \begin_inset LatexCommand \index{script, creating}
2703
2704 \end_inset
2705
2706 to demonstrate this model
2707 \begin_inset LatexCommand \label{sec:model2.creatingScript}
2708
2709 \end_inset
2710
2711
2712 \end_layout
2713
2714 \begin_layout Standard
2715 The last step to make the model reusable is to create a script that anyone
2716 can easily run.
2717 Running the model successfully will allow a user to demonstrate the use
2718 of the model and to explore an instance it by browsing it.
2719 \end_layout
2720
2721 \begin_layout Standard
2722 ASCEND allows one to create such a script using either an editor or the
2723 tools in the Script window.
2724 \end_layout
2725
2726 \begin_layout Standard
2727 Restart the ASCEND system.
2728 You will have three windows open plus the large one which disappears by
2729 itself in a few seconds: the Script, the Library and the Console windows.
2730 \end_layout
2731
2732 \begin_layout Standard
2733 In the
2734 \series bold
2735 Script
2736 \series default
2737 window you will see the license agreement information for ASCEND.
2738 First delete the license agreement
2739 \begin_inset LatexCommand \index{license agreement}
2740
2741 \end_inset
2742
2743 from this window by doing the following two steps:
2744 \end_layout
2745
2746 \begin_layout Itemize
2747 Select the Select all tool under the Edit button.
2748
2749 \end_layout
2750
2751 \begin_layout Itemize
2752 Then select the Delete statements tool under the same button.
2753
2754 \end_layout
2755
2756 \begin_layout Standard
2757 With the window
2758 \series bold
2759 clear
2760 \series default
2761 , select the tool Record actions under the Edit button to start recording
2762 the steps you are about to undertake.
2763 \end_layout
2764
2765 \begin_layout Itemize
2766 In the Library window, under the Edit button, selec Delete all types.
2767 Hit Delete all on the small window that appears.
2768 \end_layout
2769
2770 \begin_layout Itemize
2771 Load the file vesselTabulated.a4c, the file containing the model called tabulated
2772 _vessel_values.
2773 Do this by selecting the Read types from file tool under the File button
2774 and browsing the file system to find it.
2775 If you have trouble finding it, be sure to set the Files of type window
2776 at the bottom of the file browsing window to allow all types of files to
2777 be seen.
2778 \end_layout
2779
2780 \begin_layout Itemize
2781 Select the type tabulated_vessel_values in the right Library window and
2782 compile an instance of it by selecting the Create simulation tool under
2783 the Edit button.
2784 In the small window that appears, enter the name tvv and hit OK.
2785 \end_layout
2786
2787 \begin_layout Itemize
2788 Export the instance to the Browser by selecting the Simulation to Browser
2789 tool under the Export button.
2790 \end_layout
2791
2792 \begin_layout Itemize
2793 Initialize the variable values by running the values method.
2794 Do this by selecting the Run method tool under the Edit button.
2795 Select the values method and hit OK.
2796 \end_layout
2797
2798 \begin_layout Itemize
2799 Set the fixed flags to get a well-posed problem by repeating the last step
2800 but this time select the reset method.
2801 \end_layout
2802
2803 \begin_layout Itemize
2804 Export the instance tvv to the Solver by selecting the to Solver tool under
2805 the Export button.
2806 \end_layout
2807
2808 \begin_layout Itemize
2809 Solve tvv by selecting the Solve tool under the Execute button in the Solver
2810 window.
2811 \end_layout
2812
2813 \begin_layout Itemize
2814 Return to the Script window and turn off the recording by selecting the
2815 Record actions tool under the Edit button.
2816 \end_layout
2817
2818 \begin_layout Itemize
2819 Save the script you have just created by selecting the Save tool under the
2820 File button of the Script window.
2821 Name the file vesselTabulated.a4s (note the 's' ending) to indicate it is
2822 the script to run an example problem for models in the vesselTabulated.a4c
2823 (note the 'c' ending) file.
2824 \end_layout
2825
2826 \begin_layout Itemize
2827 Exit ASCEND by selecting the Exit ASCEND tool under the File button on the
2828 Script window.
2829 The contents of the Script window will be similar to that in Figure
2830 \begin_inset LatexCommand \ref{fig:model2.scriptVesselTabulated}
2831
2832 \end_inset
2833
2834
2835 \noun off
2836 (the path to the file may differ).
2837 \end_layout
2838
2839 \begin_layout Itemize
2840 Restart ASCEND.
2841 \end_layout
2842
2843 \begin_layout Itemize
2844 Open the script you just created by selecting the Read file tool under the
2845 File button on the Script window.
2846 (Be sure you are allowing the system to see files with the ending a4s by
2847 setting the Files of type window at the bottom of the file browsing window.)
2848 \end_layout
2849
2850 \begin_layout Itemize
2851 Highlight all the instructions in this script and then execute the highlighted
2852 instructions by selecting the Statements selected tool under the Execute
2853 button.
2854 \end_layout
2855
2856 \begin_layout Standard
2857 You will run the same sequence of instructions you ran to create the script.
2858 \end_layout
2859
2860 \begin_layout Standard
2861 \begin_inset Float figure
2862 wide false
2863 sideways false
2864 status open
2865
2866 \begin_layout LyX-Code
2867 DELETE TYPES;
2868 \end_layout
2869
2870 \begin_layout LyX-Code
2871 READ FILE "C:/My Documents/1998/ascdata/vesselTabulated.a4c";
2872 \end_layout
2873
2874 \begin_layout LyX-Code
2875 COMPILE tv OF tabulated_vessel_values;
2876 \end_layout
2877
2878 \begin_layout LyX-Code
2879 BROWSE {tv};
2880 \end_layout
2881
2882 \begin_layout LyX-Code
2883 RUN {tv.reset};
2884 \end_layout
2885
2886 \begin_layout LyX-Code
2887 RUN {tv.values};
2888 \end_layout
2889
2890 \begin_layout LyX-Code
2891 SOLVE {tv} WITH QRSlv;
2892 \end_layout
2893
2894 \begin_layout Caption
2895 Script to run vesselTabulated.a4c (this is the contents of the file vesselTabulat
2896 ed.a4s
2897 \begin_inset LatexCommand \index{vesselTabultated.a4s}
2898
2899 \end_inset
2900
2901 )
2902 \begin_inset LatexCommand \label{fig:model2.scriptVesselTabulated}
2903
2904 \end_inset
2905
2906
2907 \end_layout
2908
2909 \end_inset
2910
2911
2912 \end_layout
2913
2914 \begin_layout Section
2915 Discussion
2916 \end_layout
2917
2918 \begin_layout Standard
2919 In this chapter we converted the vessel model into a form where you and
2920 others in the future will have a chance to reuse it.
2921 We did this by first adding methods to make the problem well-posed and
2922 to provide values for the fixed variables for which we readily found a
2923 solution when playing with our original model as we did in the previous
2924 chapter.
2925 We then thought of a typical use for this model and developed a parameterized
2926 version based on that use.
2927 If this model were in a library, a future user of it would most often simply
2928 have to understand the parameters to create an instance of this type of
2929 model.
2930 We next added NOTES, a form of active comments, to the model.
2931 We suggest that notes are much more useful than comments as we can provide
2932 tools that can extract them and allow us to search them, for example, to
2933 find a model with a given functionality.
2934 Finally, we showed you how to create a script by turning on a "phone" session
2935 where ASCEND records the actions one takes when loading, compiling and
2936 solving a model.
2937 One can save and play this script in the future to see a typical use of
2938 the model.
2939 \end_layout
2940
2941 \begin_layout Standard
2942 In the next chapter, we look at how we can plot the results we created in
2943 the model vesselTabulated.a4c.
2944 We will have to reuse a model someone else has put into the library of
2945 available models.
2946 In other words, the "shoe is on the other foot," and we quickly experience
2947 the difficulties with reuse first hand.
2948 We will also learn how to run a case study from which we can extract the
2949 same information with a single vessel model run multiple times.
2950 \end_layout
2951
2952 \end_body
2953 \end_document

john.pye@anu.edu.au
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