Actual source code: ex3opt_fd.c
2: static char help[] = "Finds optimal parameter P_m for the generator system while maintaining generator stability.\n";
4: /*F
6: \begin{eqnarray}
7: \frac{d \theta}{dt} = \omega_b (\omega - \omega_s)
8: \frac{2 H}{\omega_s}\frac{d \omega}{dt} & = & P_m - P_max \sin(\theta) -D(\omega - \omega_s)\\
9: \end{eqnarray}
11: F*/
13: /*
14: Solve the same optimization problem as in ex3opt.c.
15: Use finite difference to approximate the gradients.
16: */
17: #include <petsctao.h>
18: #include <petscts.h>
19: #include "ex3.h"
21: PetscErrorCode FormFunction(Tao, Vec, PetscReal *, void *);
23: PetscErrorCode monitor(Tao tao, AppCtx *ctx)
24: {
25: FILE *fp;
26: PetscInt iterate;
27: PetscReal f, gnorm, cnorm, xdiff;
28: Vec X, G;
29: const PetscScalar *x, *g;
30: TaoConvergedReason reason;
32: PetscFunctionBeginUser;
33: PetscCall(TaoGetSolutionStatus(tao, &iterate, &f, &gnorm, &cnorm, &xdiff, &reason));
34: PetscCall(TaoGetSolution(tao, &X));
35: PetscCall(TaoGetGradient(tao, &G, NULL, NULL));
36: PetscCall(VecGetArrayRead(X, &x));
37: PetscCall(VecGetArrayRead(G, &g));
38: fp = fopen("ex3opt_fd_conv.out", "a");
39: PetscCall(PetscFPrintf(PETSC_COMM_WORLD, fp, "%" PetscInt_FMT " %g %.12lf %.12lf\n", iterate, (double)gnorm, (double)PetscRealPart(x[0]), (double)PetscRealPart(g[0])));
40: PetscCall(VecRestoreArrayRead(X, &x));
41: PetscCall(VecRestoreArrayRead(G, &g));
42: fclose(fp);
43: PetscFunctionReturn(PETSC_SUCCESS);
44: }
46: int main(int argc, char **argv)
47: {
48: Vec p;
49: PetscScalar *x_ptr;
50: PetscMPIInt size;
51: AppCtx ctx;
52: Vec lowerb, upperb;
53: Tao tao;
54: KSP ksp;
55: PC pc;
56: PetscBool printtofile;
57: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
58: Initialize program
59: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
60: PetscFunctionBeginUser;
61: PetscCall(PetscInitialize(&argc, &argv, NULL, help));
62: PetscFunctionBeginUser;
63: PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
64: PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This is a uniprocessor example only!");
66: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
67: Set runtime options
68: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
69: PetscOptionsBegin(PETSC_COMM_WORLD, NULL, "Swing equation options", "");
70: {
71: ctx.beta = 2;
72: ctx.c = 10000.0;
73: ctx.u_s = 1.0;
74: ctx.omega_s = 1.0;
75: ctx.omega_b = 120.0 * PETSC_PI;
76: ctx.H = 5.0;
77: PetscCall(PetscOptionsScalar("-Inertia", "", "", ctx.H, &ctx.H, NULL));
78: ctx.D = 5.0;
79: PetscCall(PetscOptionsScalar("-D", "", "", ctx.D, &ctx.D, NULL));
80: ctx.E = 1.1378;
81: ctx.V = 1.0;
82: ctx.X = 0.545;
83: ctx.Pmax = ctx.E * ctx.V / ctx.X;
84: ctx.Pmax_ini = ctx.Pmax;
85: PetscCall(PetscOptionsScalar("-Pmax", "", "", ctx.Pmax, &ctx.Pmax, NULL));
86: ctx.Pm = 1.06;
87: PetscCall(PetscOptionsScalar("-Pm", "", "", ctx.Pm, &ctx.Pm, NULL));
88: ctx.tf = 0.1;
89: ctx.tcl = 0.2;
90: PetscCall(PetscOptionsReal("-tf", "Time to start fault", "", ctx.tf, &ctx.tf, NULL));
91: PetscCall(PetscOptionsReal("-tcl", "Time to end fault", "", ctx.tcl, &ctx.tcl, NULL));
92: printtofile = PETSC_FALSE;
93: PetscCall(PetscOptionsBool("-printtofile", "Print convergence results to file", "", printtofile, &printtofile, NULL));
94: }
95: PetscOptionsEnd();
97: /* Create TAO solver and set desired solution method */
98: PetscCall(TaoCreate(PETSC_COMM_WORLD, &tao));
99: PetscCall(TaoSetType(tao, TAOBLMVM));
100: if (printtofile) PetscCall(TaoSetMonitor(tao, (PetscErrorCode(*)(Tao, void *))monitor, (void *)&ctx, NULL));
101: PetscCall(TaoSetMaximumIterations(tao, 30));
102: /*
103: Optimization starts
104: */
105: /* Set initial solution guess */
106: PetscCall(VecCreateSeq(PETSC_COMM_WORLD, 1, &p));
107: PetscCall(VecGetArray(p, &x_ptr));
108: x_ptr[0] = ctx.Pm;
109: PetscCall(VecRestoreArray(p, &x_ptr));
111: PetscCall(TaoSetSolution(tao, p));
112: /* Set routine for function and gradient evaluation */
113: PetscCall(TaoSetObjective(tao, FormFunction, (void *)&ctx));
114: PetscCall(TaoSetGradient(tao, NULL, TaoDefaultComputeGradient, (void *)&ctx));
116: /* Set bounds for the optimization */
117: PetscCall(VecDuplicate(p, &lowerb));
118: PetscCall(VecDuplicate(p, &upperb));
119: PetscCall(VecGetArray(lowerb, &x_ptr));
120: x_ptr[0] = 0.;
121: PetscCall(VecRestoreArray(lowerb, &x_ptr));
122: PetscCall(VecGetArray(upperb, &x_ptr));
123: x_ptr[0] = 1.1;
124: PetscCall(VecRestoreArray(upperb, &x_ptr));
125: PetscCall(TaoSetVariableBounds(tao, lowerb, upperb));
127: /* Check for any TAO command line options */
128: PetscCall(TaoSetFromOptions(tao));
129: PetscCall(TaoGetKSP(tao, &ksp));
130: if (ksp) {
131: PetscCall(KSPGetPC(ksp, &pc));
132: PetscCall(PCSetType(pc, PCNONE));
133: }
135: /* SOLVE THE APPLICATION */
136: PetscCall(TaoSolve(tao));
138: PetscCall(VecView(p, PETSC_VIEWER_STDOUT_WORLD));
140: /* Free TAO data structures */
141: PetscCall(TaoDestroy(&tao));
142: PetscCall(VecDestroy(&p));
143: PetscCall(VecDestroy(&lowerb));
144: PetscCall(VecDestroy(&upperb));
145: PetscCall(PetscFinalize());
146: return 0;
147: }
149: /* ------------------------------------------------------------------ */
150: /*
151: FormFunction - Evaluates the function and corresponding gradient.
153: Input Parameters:
154: tao - the Tao context
155: X - the input vector
156: ptr - optional user-defined context, as set by TaoSetObjectiveAndGradient()
158: Output Parameters:
159: f - the newly evaluated function
160: */
161: PetscErrorCode FormFunction(Tao tao, Vec P, PetscReal *f, void *ctx0)
162: {
163: AppCtx *ctx = (AppCtx *)ctx0;
164: TS ts, quadts;
165: Vec U; /* solution will be stored here */
166: Mat A; /* Jacobian matrix */
167: PetscInt n = 2;
168: PetscReal ftime;
169: PetscInt steps;
170: PetscScalar *u;
171: const PetscScalar *x_ptr, *qx_ptr;
172: Vec q;
173: PetscInt direction[2];
174: PetscBool terminate[2];
176: PetscFunctionBeginUser;
177: PetscCall(VecGetArrayRead(P, &x_ptr));
178: ctx->Pm = x_ptr[0];
179: PetscCall(VecRestoreArrayRead(P, &x_ptr));
180: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
181: Create necessary matrix and vectors
182: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
183: PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
184: PetscCall(MatSetSizes(A, n, n, PETSC_DETERMINE, PETSC_DETERMINE));
185: PetscCall(MatSetType(A, MATDENSE));
186: PetscCall(MatSetFromOptions(A));
187: PetscCall(MatSetUp(A));
189: PetscCall(MatCreateVecs(A, &U, NULL));
191: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
192: Create timestepping solver context
193: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
194: PetscCall(TSCreate(PETSC_COMM_WORLD, &ts));
195: PetscCall(TSSetProblemType(ts, TS_NONLINEAR));
196: PetscCall(TSSetType(ts, TSCN));
197: PetscCall(TSSetIFunction(ts, NULL, (TSIFunction)IFunction, ctx));
198: PetscCall(TSSetIJacobian(ts, A, A, (TSIJacobian)IJacobian, ctx));
200: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
201: Set initial conditions
202: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
203: PetscCall(VecGetArray(U, &u));
204: u[0] = PetscAsinScalar(ctx->Pm / ctx->Pmax);
205: u[1] = 1.0;
206: PetscCall(VecRestoreArray(U, &u));
207: PetscCall(TSSetSolution(ts, U));
209: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
210: Set solver options
211: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
212: PetscCall(TSSetMaxTime(ts, 1.0));
213: PetscCall(TSSetExactFinalTime(ts, TS_EXACTFINALTIME_MATCHSTEP));
214: PetscCall(TSSetTimeStep(ts, 0.03125));
215: PetscCall(TSCreateQuadratureTS(ts, PETSC_TRUE, &quadts));
216: PetscCall(TSGetSolution(quadts, &q));
217: PetscCall(VecSet(q, 0.0));
218: PetscCall(TSSetRHSFunction(quadts, NULL, (TSRHSFunction)CostIntegrand, ctx));
219: PetscCall(TSSetFromOptions(ts));
221: direction[0] = direction[1] = 1;
222: terminate[0] = terminate[1] = PETSC_FALSE;
224: PetscCall(TSSetEventHandler(ts, 2, direction, terminate, EventFunction, PostEventFunction, (void *)ctx));
226: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
227: Solve nonlinear system
228: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
229: PetscCall(TSSolve(ts, U));
231: PetscCall(TSGetSolveTime(ts, &ftime));
232: PetscCall(TSGetStepNumber(ts, &steps));
233: PetscCall(VecGetArrayRead(q, &qx_ptr));
234: *f = -ctx->Pm + qx_ptr[0];
235: PetscCall(VecRestoreArrayRead(q, &qx_ptr));
237: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
238: Free work space. All PETSc objects should be destroyed when they are no longer needed.
239: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
240: PetscCall(MatDestroy(&A));
241: PetscCall(VecDestroy(&U));
242: PetscCall(TSDestroy(&ts));
243: PetscFunctionReturn(PETSC_SUCCESS);
244: }
246: /*TEST
248: build:
249: requires: !complex !single
251: test:
252: args: -ts_type cn -pc_type lu -tao_monitor -tao_gatol 1e-3
254: TEST*/