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\use_package amsmath 2
\use_package amssymb 2
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\use_package mathtools 1
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\index Index
\shortcut idx
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\quotes_language english
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\end_header

\begin_body

\begin_layout Chapter
Plotting
\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
plotting
\end_layout

\end_inset

 data sampled from complex models
\begin_inset CommandInset label
LatexCommand label
name "cha:plot"

\end_inset

 
\end_layout

\begin_layout Standard
Often you need a plot of data sampled from arbitrary locations in a model
 that are not naturally grouped in a single easily plotted vector.
 The 
\family typewriter
plot.a4l
\family default

\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
plot.a4l
\end_layout

\end_inset

 library provides models (
\family typewriter
plt_curve
\family default

\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
plt
\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
_
\end_layout

\end_inset

curve
\end_layout

\end_inset

, 
\family typewriter
plt_plot_symbol
\family default

\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
plt
\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
_
\end_layout

\end_inset

plot
\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
_
\end_layout

\end_inset

symbol
\end_layout

\end_inset

, and 
\family typewriter
plt_plot_integer
\family default

\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
plt
\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
_
\end_layout

\end_inset

plot
\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
_
\end_layout

\end_inset

integer
\end_layout

\end_inset

) that can be used with the Browser's Display Plot button.
 In this chapter we see how to create such a plot using the ASCEND statement
 ALIASES/IS_A to sample data from a mechanical system of stretched springs,
 masses, anchors, and fingers.
 Creating plots of time series data output from ASCEND's initial value solver
 LSODE is discussed in Chapter
\begin_inset space ~
\end_inset


\begin_inset CommandInset ref
LatexCommand vref
reference "cha:ivp"

\end_inset

.
\end_layout

\begin_layout Standard
Chemical engineers who can tolerate distillation models should visit the
 file 
\family typewriter
plotcol.a4c
\family default
 in the models library for more complicated examples of plotting and visit
 the model 
\family typewriter
simple_column_profiles
\family default

\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
simple
\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
_
\end_layout

\end_inset

column
\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
_
\end_layout

\end_inset

profiles
\end_layout

\end_inset

 in 
\family typewriter
column.a4l
\family default

\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
column.a4l
\end_layout

\end_inset

 for more complicated examples of sampling data.
 Reading this chapter first may be of help in interpreting those models.
\end_layout

\begin_layout Section
The graph we want
\end_layout

\begin_layout Standard
We want to plot the positions X1 to X3 of the connecting hooks h1, h2, and
 h3 in a mechanical system as shown in Figure
\begin_inset space ~
\end_inset


\begin_inset CommandInset ref
LatexCommand ref
reference "fig:plot.springSystem"

\end_inset


\noun off
.
 The anchor, hooks, springs, and finger (we could replace either spring
 with a block mass, also) are all separate objects which we have modeled
 very simply.
 These models are given at the end of the chapter and can also be found
 (with improvements) in 
\family typewriter
\noun default
force1d.a4c
\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
force1d.a4c
\end_layout

\end_inset


\family default
\noun off
, a model file in the distributed ASCEND libraries.
 
\end_layout

\begin_layout Standard
\begin_inset Float figure
wide false
sideways false
status open

\begin_layout Plain Layout

\noun off
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\end_inset


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\end_inset


\begin_inset Graphics
	filename howto-plotFig1.eps
	scale 80
	BoundingBox 0bp 0bp 400bp 200bp

\end_inset


\end_layout

\begin_layout Plain Layout
\begin_inset Caption Standard

\begin_layout Plain Layout
Spring test model
\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
spring test model
\end_layout

\end_inset

 system, 
\family typewriter
st
\family default

\begin_inset CommandInset label
LatexCommand label
name "fig:plot.springSystem"

\end_inset


\end_layout

\end_inset


\end_layout

\end_inset


\end_layout

\begin_layout Standard
Plotting is usually a post-solution analysis
\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
post-solution analysis
\end_layout

\end_inset

 tool, so our plots should not be entangled with the basic models or with
 the total mechanical system model, 
\family typewriter
st
\family default
.
 We might want to explain the system 
\family typewriter
st
\family default
 to someone and this could be hard to do if the code is cluttered up with
 plot information.
\end_layout

\begin_layout Section
Constructing a plot curve
\end_layout

\begin_layout Standard
The plot library models follow object-oriented thinking carefully, perhaps
 a little too carefully.
 A 
\family typewriter
plt_plot_integer
\family default
 is a plottable model built out of plt_curves which are in turn built out
 of arrays of data points from the user.
 Constructing these data arrays is the only significant challenge in using
 the plot models.
 Begin by building a new model with the system st as a part:
\end_layout

\begin_layout LyX-Code
MODEL plot_spring_test;
\end_layout

\begin_layout LyX-Code
st IS_A spring_test;
\end_layout

\begin_layout LyX-Code
Plot_X IS_A plt_plot_integer(curve_set,curves);
\end_layout

\begin_layout LyX-Code
END plot_spring_test;
\end_layout

\begin_layout Standard
We want to create a 
\family typewriter
plt_curve
\family default
 from the array of hook numbers 
\family typewriter
y_data[1..3]
\family default
 plotted against horizontal hook position 
\family typewriter
x_data[1..3]
\family default
.
 There are obvious problems with the model above: 
\family typewriter
curves
\family default
 and 
\family typewriter
curve_set
\family default
 are used without being defined, and there is no mention of 
\family typewriter
x_data
\family default
 or 
\family typewriter
y_data
\family default
.
 
\end_layout

\begin_layout Standard
Begin by using an ALIASES
\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
ALIASES
\end_layout

\end_inset

/IS_A statement to construct the array of positions 
\family typewriter
x_data
\family default
 from the variables X stored in the hooks of model 
\family typewriter
st
\family default
.
\end_layout

\begin_layout LyX-Code
x_data[Xset] ALIASES (st.h1.X,st.h2.X,st.h3.X) 
\end_layout

\begin_layout LyX-Code
    WHERE Xset IS_A set OF integer_constant;
\end_layout

\begin_layout Standard
This statement creates a set, 
\family typewriter
Xset
\family default
, indexing a new array 
\family typewriter
x_data
\family default
 with elements collected from 
\family typewriter
st
\family default
.
 Since the value of 
\family typewriter
Xset
\family default
 is not specified, it becomes by default the set [1,2,3].
\end_layout

\begin_layout Standard
Now we need the hook numbers, 
\family typewriter
y_data
\family default
.
 These do not exist in 
\family typewriter
st
\family default
, so we create them.
 We will set the numeric values of these in the 
\family typewriter
default_self
\family default
 method.
 We will include method in the final model, but do not show it here.
\end_layout

\begin_layout LyX-Code
y_data[Xset] IS_A real;
\end_layout

\begin_layout Standard
Having both 
\family typewriter
y_data
\family default
 and 
\family typewriter
x_data
\family default
, we can construct a curve from them:
\end_layout

\begin_layout LyX-Code
X_curve IS_A plt_curve(Xset,y_data,x_data);
\end_layout

\begin_layout Section
Constructing the array of curves
\end_layout

\begin_layout Standard
We have a curve, but the 
\family typewriter
plt_plot_integer
\family default
 model 
\family typewriter
Plot_x
\family default
 expects an array of curves and the set indexing this array as input.
 We can make both from 
\family typewriter
X_curve
\family default
 easily using, once again, an ALIASES/IS_A statement.
\end_layout

\begin_layout LyX-Code
curves[curve_set] ALIASES (X_curve) 
\end_layout

\begin_layout LyX-Code
    WHERE curve_set IS_A set OF integer_constant;
\end_layout

\begin_layout Standard
All the pieces are now in place, so we have the final model:
\end_layout

\begin_layout LyX-Code
MODEL plot_spring_test;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
(* create our system model and plot.
 *)
\end_layout

\begin_layout LyX-Code
st IS_A spring_test;
\end_layout

\begin_layout LyX-Code
Plot_X IS_A plt_plot_integer(curve_set,curves);
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
(* Gather the sampled data into an array *)
\end_layout

\begin_layout LyX-Code
x_data[Xset] ALIASES (st.h1.X,st.h2.X,st.h3.X)
\end_layout

\begin_layout LyX-Code
WHERE Xset IS_A set OF integer_constant;
\end_layout

\begin_layout LyX-Code
(* Create the Y coordinates *)
\end_layout

\begin_layout LyX-Code
y_data[Xset] IS_A real;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
(* create the curve *)
\end_layout

\begin_layout LyX-Code
X_curve IS_A plt_curve(Xset,y_data,x_data);
\end_layout

\begin_layout LyX-Code
(* Make X_curve into the array for plt_plot_integer *)
\end_layout

\begin_layout LyX-Code
curves[curve_set] ALIASES (X_curve) WHERE
\end_layout

\begin_layout LyX-Code
curve_set IS_A set OF integer_constant;
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
RUN st.default_self;
\end_layout

\begin_layout LyX-Code
st.s1.L0 := 0.2{m}; (* make st more interesting *)
\end_layout

\begin_layout LyX-Code
RUN Plot_X.default_self;
\end_layout

\begin_layout LyX-Code
RUN X_curve.default_self;
\end_layout

\begin_layout LyX-Code
FOR i IN Xset DO
\end_layout

\begin_layout LyX-Code
y_data[i] := i;
\end_layout

\begin_layout LyX-Code
END FOR;
\end_layout

\begin_layout LyX-Code
X_curve.legend := 'meter';
\end_layout

\begin_layout LyX-Code
Plot_X.title := 'Hook locations';
\end_layout

\begin_layout LyX-Code
Plot_X.XLabel := 'location';
\end_layout

\begin_layout LyX-Code
Plot_X.YLabel := 'hook #';
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
END plot_spring_test;
\end_layout

\begin_layout Section
Resulting position plot
\end_layout

\begin_layout Standard
We can compile the plot model and obtain the graph in with the following
 short script.
\end_layout

\begin_layout LyX-Code
READ FILE force1d.a4c;
\end_layout

\begin_layout LyX-Code
COMPILE pst OF plot_spring_test;
\end_layout

\begin_layout LyX-Code
BROWSE {pst};
\end_layout

\begin_layout LyX-Code
RUN {pst.st.reset};
\end_layout

\begin_layout LyX-Code
SOLVE {pst.st} WITH QRSlv;
\end_layout

\begin_layout LyX-Code
PLOT {pst.Plot_X} ;
\end_layout

\begin_layout LyX-Code
SHOW LAST;
\end_layout

\begin_layout Standard
We can also obtain the plot by moving to 
\family typewriter
pst.Plot_X
\family default
 in the Browser window and then pushing the Display
\begin_inset Formula $\rightarrow$
\end_inset

Plot button or then typing "Alt-d p".
 We see the hooks are positioned near 0, 230, and 370 mm.
 We also see that xgraph
\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
xgraph
\end_layout

\end_inset

 sometimes makes less than pretty graphs (Figure 
\begin_inset CommandInset ref
LatexCommand ref
reference "fig:plot.plotXforSpring"

\end_inset

).
\end_layout

\begin_layout Standard
\begin_inset Float figure
wide false
sideways false
status open

\begin_layout Plain Layout
\begin_inset Graphics
	filename howto-plotFig2.eps
	BoundingBox 30bp 0bp 480bp 460bp

\end_inset


\end_layout

\begin_layout Plain Layout
\begin_inset Caption Standard

\begin_layout Plain Layout
\begin_inset CommandInset label
LatexCommand label
name "fig:plot.plotXforSpring"

\end_inset

Plot_X in plot_spring_test
\end_layout

\end_inset


\end_layout

\end_inset


\end_layout

\begin_layout Section
1-D mechanical hook, spring, mass, anchor, and finger models
\end_layout

\begin_layout Standard
The models used in this chapter are very simple versions of masses and springs
 horizontally at rest, but possibly under tension, stretched between an
 anchor and a finger.
 Only the code absolutely necessary for this example is given here; the
 full code with methods and additional comments is given in 
\family typewriter
force1d.a4c
\family default
, an ASCEND modeling example in the library.
 
\end_layout

\begin_layout Standard
These models could easily be extended to include mass, momentum, and acceleratio
n in two or three dimensions.
 Most of the methods in the 
\family typewriter
force1d.a4c
\family default
 models are unedited from the code generated by the ASCEND Library button
 Edit
\begin_inset Formula $\rightarrow$
\end_inset

Suggest method
\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
method, Suggest method
\end_layout

\end_inset


\begin_inset Index idx
status collapsed

\begin_layout Plain Layout
Suggest method tool
\end_layout

\end_inset

.
 If you improve on these models, please share them with us and the rest
 of the ASCEND community.
\end_layout

\begin_layout LyX-Code
REQUIRE "atoms.a4l";
\end_layout

\begin_layout LyX-Code
CONSTANT spring_constant REFINES real_constant DIMENSION M/T^2;
\end_layout

\begin_layout LyX-Code
CONSTANT position_constant REFINES real_constant DIMENSION L;
\end_layout

\begin_layout LyX-Code
ATOM position REFINES distance DEFAULT 0{m};
\end_layout

\begin_layout LyX-Code
END position;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
MODEL hook;
\end_layout

\begin_layout LyX-Code
  F_left, F_right IS_A force;
\end_layout

\begin_layout LyX-Code
  F_left = F_right;
\end_layout

\begin_layout LyX-Code
  X IS_A position;
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
  (* ATOM defaults are fine *)
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
METHOD specify;
\end_layout

\begin_layout LyX-Code
  F_right.fixed := TRUE;
\end_layout

\begin_layout LyX-Code
END specify;
\end_layout

\begin_layout LyX-Code
METHOD specify_float;
\end_layout

\begin_layout LyX-Code
END specify_float;
\end_layout

\begin_layout LyX-Code
END hook;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
MODEL massless_spring(
\end_layout

\begin_layout LyX-Code
  k IS_A spring_constant;
\end_layout

\begin_layout LyX-Code
  h_left WILL_BE hook;
\end_layout

\begin_layout LyX-Code
  h_right WILL_BE hook;
\end_layout

\begin_layout LyX-Code
) WHERE (
\end_layout

\begin_layout LyX-Code
  h_left, h_right WILL_NOT_BE_THE_SAME;
\end_layout

\begin_layout LyX-Code
);
\end_layout

\begin_layout LyX-Code
  L0, dx IS_A distance;
\end_layout

\begin_layout LyX-Code
  h_right.X = h_left.X + L0 + dx;
\end_layout

\begin_layout LyX-Code
  F = k * dx;
\end_layout

\begin_layout LyX-Code
  h_left.F_right = F;
\end_layout

\begin_layout LyX-Code
  h_right.F_left = F;
\end_layout

\begin_layout LyX-Code
  F IS_A force;
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
  dx := 1{cm};
\end_layout

\begin_layout LyX-Code
  L0 := 10{cm};
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
METHOD specify;
\end_layout

\begin_layout LyX-Code
  L0.fixed := TRUE;
\end_layout

\begin_layout LyX-Code
  RUN h_left.reset;
\end_layout

\begin_layout LyX-Code
  RUN h_right.reset;
\end_layout

\begin_layout LyX-Code
  h_left.F_right.fixed := FALSE;
\end_layout

\begin_layout LyX-Code
  h_left.X.fixed := TRUE;
\end_layout

\begin_layout LyX-Code
END specify;
\end_layout

\begin_layout LyX-Code
METHOD specify_float;
\end_layout

\begin_layout LyX-Code
  L0.fixed := TRUE;
\end_layout

\begin_layout LyX-Code
  RUN h_left.specify_float;
\end_layout

\begin_layout LyX-Code
  RUN h_right.specify_float;
\end_layout

\begin_layout LyX-Code
END specify_float;
\end_layout

\begin_layout LyX-Code
END massless_spring;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
MODEL massless_block(
\end_layout

\begin_layout LyX-Code
  h_left WILL_BE hook;
\end_layout

\begin_layout LyX-Code
  h_right WILL_BE hook;
\end_layout

\begin_layout LyX-Code
) WHERE (
\end_layout

\begin_layout LyX-Code
  h_left, h_right WILL_NOT_BE_THE_SAME;
\end_layout

\begin_layout LyX-Code
);
\end_layout

\begin_layout LyX-Code
  width IS_A distance;
\end_layout

\begin_layout LyX-Code
  h_left.F_right = h_right.F_left;
\end_layout

\begin_layout LyX-Code
  h_right.X = h_left.X + width;
\end_layout

\begin_layout LyX-Code
  X "center of the block" IS_A position;
\end_layout

\begin_layout LyX-Code
  X = width/2 +  h_left.X;
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
  width := 3{cm};
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
METHOD specify;
\end_layout

\begin_layout LyX-Code
  width.fixed := TRUE;
\end_layout

\begin_layout LyX-Code
  RUN h_left.reset;
\end_layout

\begin_layout LyX-Code
  h_left.F_right.fixed := FALSE;
\end_layout

\begin_layout LyX-Code
  h_left.X.fixed := TRUE;
\end_layout

\begin_layout LyX-Code
  RUN h_right.reset;
\end_layout

\begin_layout LyX-Code
END specify;
\end_layout

\begin_layout LyX-Code
METHOD specify_float;
\end_layout

\begin_layout LyX-Code
  width.fixed := TRUE;
\end_layout

\begin_layout LyX-Code
  RUN h_left.specify_float;
\end_layout

\begin_layout LyX-Code
  RUN h_right.specify_float;
\end_layout

\begin_layout LyX-Code
END specify_float;
\end_layout

\begin_layout LyX-Code
END massless_block;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
MODEL anchor(
\end_layout

\begin_layout LyX-Code
  x IS_A position_constant;
\end_layout

\begin_layout LyX-Code
  h_right WILL_BE hook;
\end_layout

\begin_layout LyX-Code
);
\end_layout

\begin_layout LyX-Code
  h_right.X = x;
\end_layout

\begin_layout LyX-Code
  F = h_right.F_left;
\end_layout

\begin_layout LyX-Code
  F IS_A force;
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
METHOD specify;
\end_layout

\begin_layout LyX-Code
  RUN h_right.reset;
\end_layout

\begin_layout LyX-Code
END specify;
\end_layout

\begin_layout LyX-Code
METHOD specify_float;
\end_layout

\begin_layout LyX-Code
END specify_float;
\end_layout

\begin_layout LyX-Code
END anchor;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
MODEL finger(
\end_layout

\begin_layout LyX-Code
  h1 WILL_BE hook;
\end_layout

\begin_layout LyX-Code
);
\end_layout

\begin_layout LyX-Code
  pull IS_A force;
\end_layout

\begin_layout LyX-Code
  h1.F_right = pull;
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
  pull := 3{N};
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
END finger;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
MODEL finger_test;
\end_layout

\begin_layout LyX-Code
NOTES 'ascii-picture' SELF {
\end_layout

\begin_layout LyX-Code
                        ___     __
\end_layout

\begin_layout LyX-Code

\backslash

\backslash
--O--/
\backslash
/
\backslash
/
\backslash
/
\backslash
/
\backslash
/--O--|   |--O(_ 
\backslash

\end_layout

\begin_layout LyX-Code
                       |___|     
\backslash
 
\backslash

\end_layout

\begin_layout LyX-Code
(reference)-h1-(s1)-h2-(m1)-h3-(pinky)
\end_layout

\begin_layout LyX-Code
}
\end_layout

\begin_layout LyX-Code
END NOTES;
\end_layout

\begin_layout LyX-Code
  h1 IS_A hook;
\end_layout

\begin_layout LyX-Code
  s1 IS_A massless_spring(100{kg/s^2},h1,h2);
\end_layout

\begin_layout LyX-Code
  h2 IS_A hook;
\end_layout

\begin_layout LyX-Code
  m1 IS_A massless_block(h2,h3);
\end_layout

\begin_layout LyX-Code
  h3 IS_A hook;
\end_layout

\begin_layout LyX-Code
  pinky IS_A finger(h3);
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
  RUN h1.default_self;
\end_layout

\begin_layout LyX-Code
  RUN h2.default_self;
\end_layout

\begin_layout LyX-Code
  RUN h3.default_self;
\end_layout

\begin_layout LyX-Code
  RUN m1.default_self;
\end_layout

\begin_layout LyX-Code
  RUN pinky.default_self;
\end_layout

\begin_layout LyX-Code
  RUN reference.default_self;
\end_layout

\begin_layout LyX-Code
  RUN s1.default_self;
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
METHOD specify;
\end_layout

\begin_layout LyX-Code
  RUN m1.specify_float;
\end_layout

\begin_layout LyX-Code
  RUN pinky.reset;
\end_layout

\begin_layout LyX-Code
  RUN reference.specify_float;
\end_layout

\begin_layout LyX-Code
  RUN s1.specify_float;
\end_layout

\begin_layout LyX-Code
END specify;
\end_layout

\begin_layout LyX-Code
END finger_test;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
MODEL spring_test;
\end_layout

\begin_layout LyX-Code
NOTES 'ascii-picture' SELF {
\end_layout

\begin_layout LyX-Code

\backslash

\backslash
--O--/
\backslash
/
\backslash
/
\backslash
/
\backslash
/
\backslash
/--O--
\backslash
/
\backslash
/
\backslash
--O(
\backslash

\end_layout

\begin_layout LyX-Code
(reference)-h1-(s1)-h2-(s2)-h3-(pinky)
\end_layout

\begin_layout LyX-Code
}
\end_layout

\begin_layout LyX-Code
END NOTES;
\end_layout

\begin_layout LyX-Code
  reference IS_A anchor(0.0{m},h1);
\end_layout

\begin_layout LyX-Code
  h1 IS_A hook;
\end_layout

\begin_layout LyX-Code
  s1 IS_A massless_spring(100{kg/s^2},h1,h2);
\end_layout

\begin_layout LyX-Code
  h2 IS_A hook;
\end_layout

\begin_layout LyX-Code
  s2 IS_A massless_spring(75{kg/s^2},h2,h3);
\end_layout

\begin_layout LyX-Code
  h3 IS_A hook;
\end_layout

\begin_layout LyX-Code
  pinky IS_A finger(h3);
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
  RUN h1.default_self;
\end_layout

\begin_layout LyX-Code
  RUN h2.default_self;
\end_layout

\begin_layout LyX-Code
  RUN h3.default_self;
\end_layout

\begin_layout LyX-Code
  RUN s2.default_self;
\end_layout

\begin_layout LyX-Code
  RUN pinky.default_self;
\end_layout

\begin_layout LyX-Code
  RUN reference.default_self;
\end_layout

\begin_layout LyX-Code
  RUN s1.default_self;
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
METHOD specify;
\end_layout

\begin_layout LyX-Code
  RUN pinky.reset;
\end_layout

\begin_layout LyX-Code
  RUN reference.specify_float;
\end_layout

\begin_layout LyX-Code
  RUN s1.specify_float;
\end_layout

\begin_layout LyX-Code
  RUN s2.specify_float;
\end_layout

\begin_layout LyX-Code
END specify;
\end_layout

\begin_layout LyX-Code
END spring_test;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
REQUIRE "plot.a4l";
\end_layout

\begin_layout LyX-Code
MODEL plot_spring_test;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
  (* create our model *)
\end_layout

\begin_layout LyX-Code
  st IS_A spring_test;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
  (* Now gather the sampled data into an array for plotting *)
\end_layout

\begin_layout LyX-Code
  x_data[Xset] ALIASES (st.h1.X,st.h2.X,st.h3.X)
\end_layout

\begin_layout LyX-Code
WHERE Xset IS_A set OF integer_constant;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
(* Now create the Y coordinates of the plot since there is no
\end_layout

\begin_layout LyX-Code
 * natural Y coordinate in our MODEL.
\end_layout

\begin_layout LyX-Code
 *)
\end_layout

\begin_layout LyX-Code
  y_data[Xset] IS_A real; (* all will be assigned to 1.0 *)
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
  X_curve IS_A plt_curve(Xset,y_data,x_data);
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
  (* Make X_curve into the expected array for plt_plot *)
\end_layout

\begin_layout LyX-Code
  curves[curve_set] ALIASES (X_curve) WHERE
\end_layout

\begin_layout LyX-Code
  curve_set IS_A set OF integer_constant;
\end_layout

\begin_layout LyX-Code

\end_layout

\begin_layout LyX-Code
  Plot_X IS_A plt_plot_integer(curve_set,curves);
\end_layout

\begin_layout LyX-Code
METHODS
\end_layout

\begin_layout LyX-Code
METHOD default_self;
\end_layout

\begin_layout LyX-Code
  RUN st.default_self;
\end_layout

\begin_layout LyX-Code
  st.s1.L0 := 0.2{m};
\end_layout

\begin_layout LyX-Code
  RUN X_curve.default_self;
\end_layout

\begin_layout LyX-Code
  RUN Plot_X.default_self;
\end_layout

\begin_layout LyX-Code
  FOR i IN Xset DO
\end_layout

\begin_layout LyX-Code
    y_data[i] := i;
\end_layout

\begin_layout LyX-Code
  END FOR;
\end_layout

\begin_layout LyX-Code
  X_curve.legend := 'meter';
\end_layout

\begin_layout LyX-Code
  Plot_X.title := 'Hook locations';
\end_layout

\begin_layout LyX-Code
  Plot_X.XLabel := 'location {m}';
\end_layout

\begin_layout LyX-Code
  Plot_X.YLabel := 'hook #';
\end_layout

\begin_layout LyX-Code
END default_self;
\end_layout

\begin_layout LyX-Code
END plot_spring_test;
\end_layout

\begin_layout Standard

\end_layout

\end_body
\end_document