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// $Header: $ |
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|
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#include "ctypes_def.h" |
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|
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#if TYPE == FLOAT |
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#define PCG spcg |
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#elif TYPE == DOUBLE |
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#define PCG dpcg |
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#elif TYPE == COMPLEXFLOAT |
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#define PCG cpcg |
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#elif TYPE == COMPLEXDOUBLE |
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#define PCG zpcg |
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#endif |
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|
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|
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int PCG( int n, int maxit, RTYPE tol, |
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void (*amult)(int n, CTYPE *x, CTYPE *y, void **data), |
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void (*msolve)(int n, CTYPE *x, CTYPE *y, void **data), |
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CTYPE *b, CTYPE *x, RTYPE *rnorm1, |
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void **adata, void **mdata) |
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{ |
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int k,i; |
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RTYPE rnorm, bnorm; |
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CTYPE gamma, alpha, beta, beta_old; |
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CTYPE *r, *z, *p, *Ap; |
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|
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k = 0; |
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/* Compute norm of rhs and return if rhs is zero. */ |
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bnorm = NRM2(n,b,1); |
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if (bnorm == RZERO) |
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{ |
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memset(x,0,n*sizeof(CTYPE)); |
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*rnorm1 = RZERO; |
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return k; |
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} |
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|
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r = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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Ap = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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|
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/* z = A x */ |
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amult(n,x,Ap,adata); |
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|
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/* r = b - A x */ |
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for (i=0;i<n;i++) |
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r[i] = b[i] - Ap[i]; |
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rnorm = NRM2(n,r,1); |
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|
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/* Test if initial guess satisfies tolerance */ |
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if (rnorm < tol*bnorm) |
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{ |
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*rnorm1 = rnorm/bnorm; |
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free(r); |
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free(Ap); |
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return k; |
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} |
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|
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z = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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p = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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/* solve M z = r */ |
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if (msolve) |
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msolve(n,r,z,mdata); |
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else |
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memcpy(z, r, n*sizeof(CTYPE)); |
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|
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/* p = z */ |
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memcpy(p,z,n*sizeof(CTYPE)); |
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|
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/* < r, z > */ |
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beta_old = DOTC(n,z,1,r,1); |
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|
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for (k=0; k<maxit && rnorm >= tol*bnorm; k++) |
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{ |
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/* Compute A p */ |
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amult(n,p,Ap,adata); |
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|
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/* < p, A p > */ |
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alpha = DOTC(n,Ap,1,p,1); |
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|
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/* x = x + a*p; r = r - a*A p */ |
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gamma = beta_old / alpha; |
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AXPY(n,gamma,p,1,x,1); |
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AXPY(n,-gamma,Ap,1,r,1); |
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rnorm = NRM2(n,r,1); |
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|
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/* solve M z = r */ |
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if (msolve) |
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msolve(n,r,z,mdata); |
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else |
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memcpy(z, r, n*sizeof(CTYPE)); |
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|
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/* beta = <r, z> */ |
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beta = DOTC(n,z,1,r,1); |
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gamma = beta / beta_old; |
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beta_old = beta; |
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/* p = z + gamma*p */ |
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for (i=0;i<n;i++) |
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p[i] = z[i] + gamma*p[i]; |
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} |
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|
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free(r); |
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free(z); |
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free(p); |
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free(Ap); |
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|
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*rnorm1 = rnorm/bnorm; |
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return k; |
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} |
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|
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|
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#ifdef NOBLAS |
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|
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int PCG( int n, int maxit, RTYPE tol, |
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void (*amult)(int n, CTYPE *x, CTYPE *y, void **data), |
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void (*msolve)(int n, CTYPE *x, CTYPE *y, void **data), |
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CTYPE *b, CTYPE *x, RTYPE *rnorm1, |
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void **adata, void **mdata) |
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{ |
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int k,i; |
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RTYPE rnorm, bnorm; |
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CTYPE gamma, alpha, beta, beta_old; |
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CTYPE *r, *z, *p, *Ap; |
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|
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k=0; |
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|
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/* Compute norm of rhs and return if rhs is zero. */ |
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bnorm = RZERO; |
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for (i=0;i<n;i++) |
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bnorm = CONJ(b[i])*b[i]; |
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bnorm = sqrt(bnorm); |
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if (bnorm == RZERO) |
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{ |
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memset(x,0,n*sizeof(CTYPE)); |
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*rnorm1 = RZERO; |
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return k; |
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} |
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|
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r = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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Ap = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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|
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/* z = A x */ |
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amult(n,x,Ap,adata); |
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|
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/* r = b - A x */ |
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rnorm = RZERO; |
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for (i=0;i<n;i++) |
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{ |
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r[i] = b[i] - Ap[i]; |
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rnorm += CONJ(r[i])*r[i]; |
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} |
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rnorm = sqrt(rnorm); |
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|
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/* Test if initial guess satisfies tolerance */ |
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if (rnorm < tol*bnorm) |
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{ |
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*rnorm1 = rnorm/bnorm; |
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free(r); |
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free(Ap); |
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return k; |
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} |
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|
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z = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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p = (CTYPE *)malloc(n*sizeof(CTYPE)); |
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/* solve M z = r */ |
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if (msolve) |
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msolve(n,r,z,mdata); |
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else |
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memcpy(z, r, n*sizeof(CTYPE)); |
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|
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/* p = z */ |
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memcpy(p,z,n*sizeof(CTYPE)); |
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|
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/* < r, z > */ |
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beta_old = CZERO; |
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for (i=0; i<n; i++) |
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beta_old += CONJ(z[i]) * r[i]; |
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|
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for (k=0; k<maxit && rnorm >= tol*bnorm; k++) |
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{ |
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/* Compute A p */ |
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amult(n,p,Ap,adata); |
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|
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/* < p, A p > */ |
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alpha = CZERO; |
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for (i=0;i<n;i++) |
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alpha += CONJ(Ap[i]) * p[i]; |
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|
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/* x = x + a*p; r = r - a*A p */ |
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gamma = beta_old / alpha; |
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rnorm = RZERO; |
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for (i=0;i<n;i++) |
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{ |
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x[i] += gamma*p[i]; |
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r[i] -= gamma*Ap[i]; |
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rnorm += SQR(r[i]); |
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} |
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rnorm = sqrt(rnorm); |
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|
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/* solve M z = r */ |
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if (msolve) |
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msolve(n,r,z,mdata); |
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else |
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memcpy(z, r, n*sizeof(CTYPE)); |
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|
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/* beta = <r, z> */ |
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beta = CZERO; |
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for (i=0;i<n;i++) |
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beta += CONJ(z[i]) * r[i]; |
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gamma = beta / beta_old; |
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beta_old = beta; |
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/* p = z + b*p */ |
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for (i=0;i<n;i++) |
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p[i] = z[i] + gamma*p[i]; |
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} |
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|
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free(r); |
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free(z); |
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free(p); |
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free(Ap); |
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|
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*rnorm1 = rnorm/bnorm; |
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return k; |
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} |
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#endif |
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|
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#undef PCG |
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#include "ctypes_undef.h" |