models/johnpye/dsg_array.a4c

REQUIRE "ivpsystem.a4l";
REQUIRE "johnpye/dsg.a4c";

MODEL dsg_array;

	t IS_A time;	
	dz IS_A distance;
	n IS_A integer_constant;
	n :== 3;

	node[1..n] IS_A dsg;
	
	(* central difference *)
	(*
	FOR i IN [2..(n-1)] CREATE
		node[i].dp_dz = (node[i+1].p - node[i-1].p)/(2*dz);
		node[i].dmdot_dz = (node[i+1].mdot - node[i-1].mdot)/(2*dz);
		node[i].dmdoth_dz = (node[i+1].mdoth - node[i-1].mdoth)/(2*dz);
		node[i].drhovel2_dz = (node[i+1].rhovel2 - node[i-1].rhovel2)/(2*dz);
		node[i].dekdot_dz = (node[i+1].ekdot - node[i-1].ekdot)/(2*dz);
	END FOR;
	*)

	(* backward difference *)
	FOR i IN [2..n] CREATE
		dz_p[i]:       node[i].dp_dz = (node[i].p - node[i-1].p)/dz;
		dz_mdot[i]:    node[i].dmdot_dz = (node[i].mdot - node[i-1].mdot)/dz;
		dz_mdoth[i]:   node[i].dmdoth_dz = (node[i].mdoth - node[i-1].mdoth)/dz;
		dz_rhovel2[i]: node[i].drhovel2_dz = (node[i].rhovel2 - node[i-1].rhovel2)/dz;
		dz_ekdot[i]:   node[i].dekdot_dz = (node[i].ekdot - node[i-1].ekdot)/dz;
	END FOR;

	(* forward difference *)
	(*
	FOR i IN [1] CREATE
		node[i].dp_dz = (node[i+1].p - node[i].p)/dz;
		node[i].dmdot_dz = (node[i+1].mdot - node[i].mdot)/dz;
		node[i].dmdoth_dz = (node[i+1].mdoth - node[i].mdoth)/dz;
		node[i].drhovel2_dz = (node[i+1].rhovel2 - node[i].rhovel2)/dz;
		node[i].dekdot_dz = (node[i+1].ekdot - node[i].ekdot)/dz;
	END FOR;
	*)
	
METHODS
METHOD specify;
	FOR i IN [1..n] DO
		RUN node[i].specify;
	END FOR;
END specify;

METHOD values;
	FOR i IN [1..n] DO
		RUN node[i].values;
	END FOR;
END values;

METHOD on_load;
	RUN specify;
	RUN values;
END on_load;

END dsg_array;
1	johnpye	748	REQUIRE "ivpsystem.a4l";
2			REQUIRE "johnpye/dsg.a4c";
3
4			MODEL dsg_array;
5
6			t IS_A time;
7			dz IS_A distance;
8			n IS_A integer_constant;
9	johnpye	758	n :== 3;
10	johnpye	748
11			node[1..n] IS_A dsg;
12
13			(* central difference *)
14	johnpye	758	(*
15	johnpye	748	FOR i IN [2..(n-1)] CREATE
16			node[i].dp_dz = (node[i+1].p - node[i-1].p)/(2*dz);
17			node[i].dmdot_dz = (node[i+1].mdot - node[i-1].mdot)/(2*dz);
18			node[i].dmdoth_dz = (node[i+1].mdoth - node[i-1].mdoth)/(2*dz);
19	johnpye	758	node[i].drhovel2_dz = (node[i+1].rhovel2 - node[i-1].rhovel2)/(2*dz);
20	johnpye	748	node[i].dekdot_dz = (node[i+1].ekdot - node[i-1].ekdot)/(2*dz);
21			END FOR;
22	johnpye	758	*)
23
24	johnpye	748	(* backward difference *)
25	johnpye	758	FOR i IN [2..n] CREATE
26			dz_p[i]: node[i].dp_dz = (node[i].p - node[i-1].p)/dz;
27			dz_mdot[i]: node[i].dmdot_dz = (node[i].mdot - node[i-1].mdot)/dz;
28			dz_mdoth[i]: node[i].dmdoth_dz = (node[i].mdoth - node[i-1].mdoth)/dz;
29			dz_rhovel2[i]: node[i].drhovel2_dz = (node[i].rhovel2 - node[i-1].rhovel2)/dz;
30			dz_ekdot[i]: node[i].dekdot_dz = (node[i].ekdot - node[i-1].ekdot)/dz;
31	johnpye	748	END FOR;
32
33			(* forward difference *)
34	johnpye	758	(*
35	johnpye	748	FOR i IN [1] CREATE
36			node[i].dp_dz = (node[i+1].p - node[i].p)/dz;
37			node[i].dmdot_dz = (node[i+1].mdot - node[i].mdot)/dz;
38			node[i].dmdoth_dz = (node[i+1].mdoth - node[i].mdoth)/dz;
39	johnpye	758	node[i].drhovel2_dz = (node[i+1].rhovel2 - node[i].rhovel2)/dz;
40	johnpye	748	node[i].dekdot_dz = (node[i+1].ekdot - node[i].ekdot)/dz;
41			END FOR;
42	johnpye	758	*)
43	johnpye	748
44			METHODS
45			METHOD specify;
46			FOR i IN [1..n] DO
47			RUN node[i].specify;
48			END FOR;
49			END specify;
50
51			METHOD values;
52			FOR i IN [1..n] DO
53			RUN node[i].values;
54			END FOR;
55			END values;
56
57			METHOD on_load;
58			RUN specify;
59			RUN values;
60			END on_load;
61
62			END dsg_array;