1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */

 11: static char help[] = "Test rational function.\n\n";

 13: #include <slepcfn.h>

 15: int main(int argc,char **argv)
 16: {
 17:   FN             fn;
 18:   PetscInt       i,na,nb;
 19:   PetscScalar    x,y,yp,p[10],q[10],five=5.0,*pp,*qq;
 20:   char           strx[50],str[50];

 22:   PetscFunctionBeginUser;
 23:   PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
 24:   PetscCall(FNCreate(PETSC_COMM_WORLD,&fn));

 26:   /* polynomial p(x) */
 27:   na = 5;
 28:   p[0] = -3.1; p[1] = 1.1; p[2] = 1.0; p[3] = -2.0; p[4] = 3.5;
 29:   PetscCall(FNSetType(fn,FNRATIONAL));
 30:   PetscCall(FNRationalSetNumerator(fn,na,p));
 31:   PetscCall(FNView(fn,NULL));
 32:   x = 2.2;
 33:   PetscCall(SlepcSNPrintfScalar(strx,sizeof(strx),x,PETSC_FALSE));
 34:   PetscCall(FNEvaluateFunction(fn,x,&y));
 35:   PetscCall(FNEvaluateDerivative(fn,x,&yp));
 36:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),y,PETSC_FALSE));
 37:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f(%s)=%s\n",strx,str));
 38:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),yp,PETSC_FALSE));
 39:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f'(%s)=%s\n",strx,str));

 41:   /* inverse of polynomial 1/q(x) */
 42:   nb = 3;
 43:   q[0] = -3.1; q[1] = 1.1; q[2] = 1.0;
 44:   PetscCall(FNSetType(fn,FNRATIONAL));
 45:   PetscCall(FNRationalSetNumerator(fn,0,NULL));  /* reset previous values */
 46:   PetscCall(FNRationalSetDenominator(fn,nb,q));
 47:   PetscCall(FNView(fn,NULL));
 48:   x = 2.2;
 49:   PetscCall(SlepcSNPrintfScalar(strx,sizeof(strx),x,PETSC_FALSE));
 50:   PetscCall(FNEvaluateFunction(fn,x,&y));
 51:   PetscCall(FNEvaluateDerivative(fn,x,&yp));
 52:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),y,PETSC_FALSE));
 53:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f(%s)=%s\n",strx,str));
 54:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),yp,PETSC_FALSE));
 55:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f'(%s)=%s\n",strx,str));

 57:   /* rational p(x)/q(x) */
 58:   na = 2; nb = 3;
 59:   p[0] = 1.1; p[1] = 1.1;
 60:   q[0] = 1.0; q[1] = -2.0; q[2] = 3.5;
 61:   PetscCall(FNSetType(fn,FNRATIONAL));
 62:   PetscCall(FNRationalSetNumerator(fn,na,p));
 63:   PetscCall(FNRationalSetDenominator(fn,nb,q));
 64:   PetscCall(FNSetScale(fn,1.2,0.5));
 65:   PetscCall(FNView(fn,NULL));
 66:   x = 2.2;
 67:   PetscCall(SlepcSNPrintfScalar(strx,sizeof(strx),x,PETSC_FALSE));
 68:   PetscCall(FNEvaluateFunction(fn,x,&y));
 69:   PetscCall(FNEvaluateDerivative(fn,x,&yp));
 70:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),y,PETSC_FALSE));
 71:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f(%s)=%s\n",strx,str));
 72:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),yp,PETSC_FALSE));
 73:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f'(%s)=%s\n",strx,str));

 75:   PetscCall(FNRationalGetNumerator(fn,&na,&pp));
 76:   PetscCall(FNRationalGetDenominator(fn,&nb,&qq));
 77:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Coefficients:\n  Numerator: "));
 78:   for (i=0;i<na;i++) {
 79:     PetscCall(SlepcSNPrintfScalar(str,sizeof(str),pp[i],PETSC_FALSE));
 80:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%s ",str));
 81:   }
 82:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\n  Denominator: "));
 83:   for (i=0;i<nb;i++) {
 84:     PetscCall(SlepcSNPrintfScalar(str,sizeof(str),qq[i],PETSC_FALSE));
 85:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%s ",str));
 86:   }
 87:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\n"));
 88:   PetscCall(PetscFree(pp));
 89:   PetscCall(PetscFree(qq));

 91:   /* constant */
 92:   PetscCall(FNSetType(fn,FNRATIONAL));
 93:   PetscCall(FNRationalSetNumerator(fn,1,&five));
 94:   PetscCall(FNRationalSetDenominator(fn,0,NULL));  /* reset previous values */
 95:   PetscCall(FNView(fn,NULL));
 96:   x = 2.2;
 97:   PetscCall(SlepcSNPrintfScalar(strx,sizeof(strx),x,PETSC_FALSE));
 98:   PetscCall(FNEvaluateFunction(fn,x,&y));
 99:   PetscCall(FNEvaluateDerivative(fn,x,&yp));
100:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),y,PETSC_FALSE));
101:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f(%s)=%s\n",strx,str));
102:   PetscCall(SlepcSNPrintfScalar(str,sizeof(str),yp,PETSC_FALSE));
103:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  f'(%s)=%s\n",strx,str));

105:   PetscCall(FNDestroy(&fn));
106:   PetscCall(SlepcFinalize());
107:   return 0;
108: }

110: /*TEST

112:    test:
113:       suffix: 1
114:       nsize: 1

116: TEST*/