1 
2 static char help[] = "Finds optimal parameter P_m for the generator system while maintaining generator stability.\n";
3 
4 /*F
5 
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}
10 
11 F*/
12 
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"
20 
21 PetscErrorCode FormFunction(Tao,Vec,PetscReal*,void*);
22 
monitor(Tao tao,AppCtx * ctx)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;
31   PetscErrorCode     ierr;
32 
33   PetscFunctionBeginUser;
34   ierr = TaoGetSolutionStatus(tao,&iterate,&f,&gnorm,&cnorm,&xdiff,&reason);CHKERRQ(ierr);
35   ierr = TaoGetSolutionVector(tao,&X);CHKERRQ(ierr);
36   ierr = TaoGetGradientVector(tao,&G);CHKERRQ(ierr);
37   ierr = VecGetArrayRead(X,&x);CHKERRQ(ierr);
38   ierr = VecGetArrayRead(G,&g);CHKERRQ(ierr);
39   fp = fopen("ex3opt_fd_conv.out","a");
40   ierr = PetscFPrintf(PETSC_COMM_WORLD,fp,"%d %g %.12lf %.12lf\n",iterate,gnorm,x[0],g[0]);CHKERRQ(ierr);
41   ierr = VecRestoreArrayRead(X,&x);CHKERRQ(ierr);
42   ierr = VecRestoreArrayRead(G,&g);CHKERRQ(ierr);
43   fclose(fp);
44   PetscFunctionReturn(0);
45 }
46 
main(int argc,char ** argv)47 int main(int argc,char **argv)
48 {
49   Vec                p;
50   PetscScalar        *x_ptr;
51   PetscErrorCode     ierr;
52   PetscMPIInt        size;
53   AppCtx             ctx;
54   Vec                lowerb,upperb;
55   Tao                tao;
56   KSP                ksp;
57   PC                 pc;
58   PetscBool          printtofile;
59   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
60      Initialize program
61      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
62   ierr = PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;
63   PetscFunctionBeginUser;
64   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
65   if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!");
66 
67   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
68     Set runtime options
69     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
70   ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"Swing equation options","");CHKERRQ(ierr);
71   {
72     ctx.beta    = 2;
73     ctx.c       = 10000.0;
74     ctx.u_s     = 1.0;
75     ctx.omega_s = 1.0;
76     ctx.omega_b = 120.0*PETSC_PI;
77     ctx.H       = 5.0;
78     ierr        = PetscOptionsScalar("-Inertia","","",ctx.H,&ctx.H,NULL);CHKERRQ(ierr);
79     ctx.D       = 5.0;
80     ierr        = PetscOptionsScalar("-D","","",ctx.D,&ctx.D,NULL);CHKERRQ(ierr);
81     ctx.E       = 1.1378;
82     ctx.V       = 1.0;
83     ctx.X       = 0.545;
84     ctx.Pmax    = ctx.E*ctx.V/ctx.X;
85     ctx.Pmax_ini = ctx.Pmax;
86     ierr        = PetscOptionsScalar("-Pmax","","",ctx.Pmax,&ctx.Pmax,NULL);CHKERRQ(ierr);
87     ctx.Pm      = 1.06;
88     ierr        = PetscOptionsScalar("-Pm","","",ctx.Pm,&ctx.Pm,NULL);CHKERRQ(ierr);
89     ctx.tf      = 0.1;
90     ctx.tcl     = 0.2;
91     ierr        = PetscOptionsReal("-tf","Time to start fault","",ctx.tf,&ctx.tf,NULL);CHKERRQ(ierr);
92     ierr        = PetscOptionsReal("-tcl","Time to end fault","",ctx.tcl,&ctx.tcl,NULL);CHKERRQ(ierr);
93     printtofile = PETSC_FALSE;
94     ierr        = PetscOptionsBool("-printtofile","Print convergence results to file","",printtofile,&printtofile,NULL);CHKERRQ(ierr);
95   }
96   ierr = PetscOptionsEnd();CHKERRQ(ierr);
97 
98   /* Create TAO solver and set desired solution method */
99   ierr = TaoCreate(PETSC_COMM_WORLD,&tao);CHKERRQ(ierr);
100   ierr = TaoSetType(tao,TAOBLMVM);CHKERRQ(ierr);
101   if (printtofile) {
102     ierr = TaoSetMonitor(tao,(PetscErrorCode (*)(Tao, void*))monitor,(void *)&ctx,PETSC_NULL);CHKERRQ(ierr);
103   }
104   ierr = TaoSetMaximumIterations(tao,30);CHKERRQ(ierr);
105   /*
106      Optimization starts
107   */
108   /* Set initial solution guess */
109   ierr = VecCreateSeq(PETSC_COMM_WORLD,1,&p);CHKERRQ(ierr);
110   ierr = VecGetArray(p,&x_ptr);CHKERRQ(ierr);
111   x_ptr[0]   = ctx.Pm;
112   ierr = VecRestoreArray(p,&x_ptr);CHKERRQ(ierr);
113 
114   ierr = TaoSetInitialVector(tao,p);CHKERRQ(ierr);
115   /* Set routine for function and gradient evaluation */
116   ierr = TaoSetObjectiveRoutine(tao,FormFunction,(void *)&ctx);CHKERRQ(ierr);
117   ierr = TaoSetGradientRoutine(tao,TaoDefaultComputeGradient,(void *)&ctx);CHKERRQ(ierr);
118 
119   /* Set bounds for the optimization */
120   ierr = VecDuplicate(p,&lowerb);CHKERRQ(ierr);
121   ierr = VecDuplicate(p,&upperb);CHKERRQ(ierr);
122   ierr = VecGetArray(lowerb,&x_ptr);CHKERRQ(ierr);
123   x_ptr[0] = 0.;
124   ierr = VecRestoreArray(lowerb,&x_ptr);CHKERRQ(ierr);
125   ierr = VecGetArray(upperb,&x_ptr);CHKERRQ(ierr);
126   x_ptr[0] = 1.1;
127   ierr = VecRestoreArray(upperb,&x_ptr);CHKERRQ(ierr);
128   ierr = TaoSetVariableBounds(tao,lowerb,upperb);CHKERRQ(ierr);
129 
130   /* Check for any TAO command line options */
131   ierr = TaoSetFromOptions(tao);CHKERRQ(ierr);
132   ierr = TaoGetKSP(tao,&ksp);CHKERRQ(ierr);
133   if (ksp) {
134     ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
135     ierr = PCSetType(pc,PCNONE);CHKERRQ(ierr);
136   }
137 
138   /* SOLVE THE APPLICATION */
139   ierr = TaoSolve(tao);CHKERRQ(ierr);
140 
141   ierr = VecView(p,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
142 
143   /* Free TAO data structures */
144   ierr = TaoDestroy(&tao);CHKERRQ(ierr);
145   ierr = VecDestroy(&p);CHKERRQ(ierr);
146   ierr = VecDestroy(&lowerb);CHKERRQ(ierr);
147   ierr = VecDestroy(&upperb);CHKERRQ(ierr);
148   ierr = PetscFinalize();
149   return ierr;
150 }
151 
152 /* ------------------------------------------------------------------ */
153 /*
154    FormFunction - Evaluates the function and corresponding gradient.
155 
156    Input Parameters:
157    tao - the Tao context
158    X   - the input vector
159    ptr - optional user-defined context, as set by TaoSetObjectiveAndGradientRoutine()
160 
161    Output Parameters:
162    f   - the newly evaluated function
163 */
FormFunction(Tao tao,Vec P,PetscReal * f,void * ctx0)164 PetscErrorCode FormFunction(Tao tao,Vec P,PetscReal *f,void *ctx0)
165 {
166   AppCtx            *ctx = (AppCtx*)ctx0;
167   TS                ts,quadts;
168   Vec               U;             /* solution will be stored here */
169   Mat               A;             /* Jacobian matrix */
170   PetscErrorCode    ierr;
171   PetscInt          n = 2;
172   PetscReal         ftime;
173   PetscInt          steps;
174   PetscScalar       *u;
175   const PetscScalar *x_ptr,*qx_ptr;
176   Vec               q;
177   PetscInt          direction[2];
178   PetscBool         terminate[2];
179 
180   ierr = VecGetArrayRead(P,&x_ptr);CHKERRQ(ierr);
181   ctx->Pm = x_ptr[0];
182   ierr = VecRestoreArrayRead(P,&x_ptr);CHKERRQ(ierr);
183   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
184     Create necessary matrix and vectors
185     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
186   ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
187   ierr = MatSetSizes(A,n,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
188   ierr = MatSetType(A,MATDENSE);CHKERRQ(ierr);
189   ierr = MatSetFromOptions(A);CHKERRQ(ierr);
190   ierr = MatSetUp(A);CHKERRQ(ierr);
191 
192   ierr = MatCreateVecs(A,&U,NULL);CHKERRQ(ierr);
193 
194   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
195      Create timestepping solver context
196      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
197   ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
198   ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
199   ierr = TSSetType(ts,TSCN);CHKERRQ(ierr);
200   ierr = TSSetIFunction(ts,NULL,(TSIFunction) IFunction,ctx);CHKERRQ(ierr);
201   ierr = TSSetIJacobian(ts,A,A,(TSIJacobian)IJacobian,ctx);CHKERRQ(ierr);
202 
203   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
204      Set initial conditions
205    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
206   ierr = VecGetArray(U,&u);CHKERRQ(ierr);
207   u[0] = PetscAsinScalar(ctx->Pm/ctx->Pmax);
208   u[1] = 1.0;
209   ierr = VecRestoreArray(U,&u);CHKERRQ(ierr);
210   ierr = TSSetSolution(ts,U);CHKERRQ(ierr);
211 
212   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
213      Set solver options
214    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
215   ierr = TSSetMaxTime(ts,1.0);CHKERRQ(ierr);
216   ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_MATCHSTEP);CHKERRQ(ierr);
217   ierr = TSSetTimeStep(ts,0.03125);CHKERRQ(ierr);
218   ierr = TSCreateQuadratureTS(ts,PETSC_TRUE,&quadts);CHKERRQ(ierr);
219   ierr = TSGetSolution(quadts,&q);CHKERRQ(ierr);
220   ierr = VecSet(q,0.0);CHKERRQ(ierr);
221   ierr = TSSetRHSFunction(quadts,NULL,(TSRHSFunction)CostIntegrand,ctx);CHKERRQ(ierr);
222   ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
223 
224   direction[0] = direction[1] = 1;
225   terminate[0] = terminate[1] = PETSC_FALSE;
226 
227   ierr = TSSetEventHandler(ts,2,direction,terminate,EventFunction,PostEventFunction,(void*)ctx);CHKERRQ(ierr);
228 
229   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
230      Solve nonlinear system
231      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
232   ierr = TSSolve(ts,U);CHKERRQ(ierr);
233 
234   ierr = TSGetSolveTime(ts,&ftime);CHKERRQ(ierr);
235   ierr = TSGetStepNumber(ts,&steps);CHKERRQ(ierr);
236   ierr = VecGetArrayRead(q,&qx_ptr);CHKERRQ(ierr);
237   *f   = -ctx->Pm + qx_ptr[0];
238   ierr = VecRestoreArrayRead(q,&qx_ptr);CHKERRQ(ierr);
239 
240   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
241      Free work space.  All PETSc objects should be destroyed when they are no longer needed.
242    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
243   ierr = MatDestroy(&A);CHKERRQ(ierr);
244   ierr = VecDestroy(&U);CHKERRQ(ierr);
245   ierr = TSDestroy(&ts);CHKERRQ(ierr);
246   return 0;
247 }
248 
249 /*TEST
250 
251    build:
252       requires: !complex !single
253 
254    test:
255       args: -ts_type cn -pc_type lu -tao_monitor -tao_gatol 1e-3
256 
257 TEST*/
258