#include "blaswrap.h" /* chpt21.f -- translated by f2c (version 20061008). You must link the resulting object file with libf2c: on Microsoft Windows system, link with libf2c.lib; on Linux or Unix systems, link with .../path/to/libf2c.a -lm or, if you install libf2c.a in a standard place, with -lf2c -lm -- in that order, at the end of the command line, as in cc *.o -lf2c -lm Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., http://www.netlib.org/f2c/libf2c.zip */ #include "f2c.h" /* Table of constant values */ static complex c_b1 = {0.f,0.f}; static complex c_b2 = {1.f,0.f}; static integer c__1 = 1; /* Subroutine */ int chpt21_(integer *itype, char *uplo, integer *n, integer * kband, complex *ap, real *d__, real *e, complex *u, integer *ldu, complex *vp, complex *tau, complex *work, real *rwork, real *result) { /* System generated locals */ integer u_dim1, u_offset, i__1, i__2, i__3, i__4, i__5, i__6; real r__1, r__2; complex q__1, q__2, q__3; /* Local variables */ static integer j, jp, jr, jp1, lap; static real ulp; extern /* Subroutine */ int chpr_(char *, integer *, real *, complex *, integer *, complex *); static real unfl; static complex temp; extern /* Subroutine */ int chpr2_(char *, integer *, complex *, complex * , integer *, complex *, integer *, complex *), cgemm_( char *, char *, integer *, integer *, integer *, complex *, complex *, integer *, complex *, integer *, complex *, complex *, integer *); extern /* Complex */ VOID cdotc_(complex *, integer *, complex *, integer *, complex *, integer *); extern logical lsame_(char *, char *); static integer iinfo; static real anorm; extern /* Subroutine */ int ccopy_(integer *, complex *, integer *, complex *, integer *), chpmv_(char *, integer *, complex *, complex *, complex *, integer *, complex *, complex *, integer *); static char cuplo[1]; static complex vsave; extern /* Subroutine */ int caxpy_(integer *, complex *, complex *, integer *, complex *, integer *); static logical lower; static real wnorm; extern doublereal clange_(char *, integer *, integer *, complex *, integer *, real *), clanhp_(char *, char *, integer *, complex *, real *), slamch_(char *); extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), claset_(char *, integer *, integer *, complex *, complex *, complex *, integer *), cupmtr_(char *, char *, char *, integer *, integer *, complex *, complex *, complex *, integer *, complex *, integer *); /* -- LAPACK test routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 Purpose ======= CHPT21 generally checks a decomposition of the form A = U S U* where * means conjugate transpose, A is hermitian, U is unitary, and S is diagonal (if KBAND=0) or (real) symmetric tridiagonal (if KBAND=1). If ITYPE=1, then U is represented as a dense matrix, otherwise the U is expressed as a product of Householder transformations, whose vectors are stored in the array "V" and whose scaling constants are in "TAU"; we shall use the letter "V" to refer to the product of Householder transformations (which should be equal to U). Specifically, if ITYPE=1, then: RESULT(1) = | A - U S U* | / ( |A| n ulp ) *and* RESULT(2) = | I - UU* | / ( n ulp ) If ITYPE=2, then: RESULT(1) = | A - V S V* | / ( |A| n ulp ) If ITYPE=3, then: RESULT(1) = | I - UV* | / ( n ulp ) Packed storage means that, for example, if UPLO='U', then the columns of the upper triangle of A are stored one after another, so that A(1,j+1) immediately follows A(j,j) in the array AP. Similarly, if UPLO='L', then the columns of the lower triangle of A are stored one after another in AP, so that A(j+1,j+1) immediately follows A(n,j) in the array AP. This means that A(i,j) is stored in: AP( i + j*(j-1)/2 ) if UPLO='U' AP( i + (2*n-j)*(j-1)/2 ) if UPLO='L' The array VP bears the same relation to the matrix V that A does to AP. For ITYPE > 1, the transformation U is expressed as a product of Householder transformations: If UPLO='U', then V = H(n-1)...H(1), where H(j) = I - tau(j) v(j) v(j)* and the first j-1 elements of v(j) are stored in V(1:j-1,j+1), (i.e., VP( j*(j+1)/2 + 1 : j*(j+1)/2 + j-1 ) ), the j-th element is 1, and the last n-j elements are 0. If UPLO='L', then V = H(1)...H(n-1), where H(j) = I - tau(j) v(j) v(j)* and the first j elements of v(j) are 0, the (j+1)-st is 1, and the (j+2)-nd through n-th elements are stored in V(j+2:n,j) (i.e., in VP( (2*n-j)*(j-1)/2 + j+2 : (2*n-j)*(j-1)/2 + n ) .) Arguments ========= ITYPE (input) INTEGER Specifies the type of tests to be performed. 1: U expressed as a dense unitary matrix: RESULT(1) = | A - U S U* | / ( |A| n ulp ) *and* RESULT(2) = | I - UU* | / ( n ulp ) 2: U expressed as a product V of Housholder transformations: RESULT(1) = | A - V S V* | / ( |A| n ulp ) 3: U expressed both as a dense unitary matrix and as a product of Housholder transformations: RESULT(1) = | I - UV* | / ( n ulp ) UPLO (input) CHARACTER If UPLO='U', the upper triangle of A and V will be used and the (strictly) lower triangle will not be referenced. If UPLO='L', the lower triangle of A and V will be used and the (strictly) upper triangle will not be referenced. N (input) INTEGER The size of the matrix. If it is zero, CHPT21 does nothing. It must be at least zero. KBAND (input) INTEGER The bandwidth of the matrix. It may only be zero or one. If zero, then S is diagonal, and E is not referenced. If one, then S is symmetric tri-diagonal. AP (input) COMPLEX array, dimension (N*(N+1)/2) The original (unfactored) matrix. It is assumed to be hermitian, and contains the columns of just the upper triangle (UPLO='U') or only the lower triangle (UPLO='L'), packed one after another. D (input) REAL array, dimension (N) The diagonal of the (symmetric tri-) diagonal matrix. E (input) REAL array, dimension (N) The off-diagonal of the (symmetric tri-) diagonal matrix. E(1) is the (1,2) and (2,1) element, E(2) is the (2,3) and (3,2) element, etc. Not referenced if KBAND=0. U (input) COMPLEX array, dimension (LDU, N) If ITYPE=1 or 3, this contains the unitary matrix in the decomposition, expressed as a dense matrix. If ITYPE=2, then it is not referenced. LDU (input) INTEGER The leading dimension of U. LDU must be at least N and at least 1. VP (input) REAL array, dimension (N*(N+1)/2) If ITYPE=2 or 3, the columns of this array contain the Householder vectors used to describe the unitary matrix in the decomposition, as described in purpose. *NOTE* If ITYPE=2 or 3, V is modified and restored. The subdiagonal (if UPLO='L') or the superdiagonal (if UPLO='U') is set to one, and later reset to its original value, during the course of the calculation. If ITYPE=1, then it is neither referenced nor modified. TAU (input) COMPLEX array, dimension (N) If ITYPE >= 2, then TAU(j) is the scalar factor of v(j) v(j)* in the Householder transformation H(j) of the product U = H(1)...H(n-2) If ITYPE < 2, then TAU is not referenced. WORK (workspace) COMPLEX array, dimension (N**2) Workspace. RWORK (workspace) REAL array, dimension (N) Workspace. RESULT (output) REAL array, dimension (2) The values computed by the two tests described above. The values are currently limited to 1/ulp, to avoid overflow. RESULT(1) is always modified. RESULT(2) is modified only if ITYPE=1. ===================================================================== Constants Parameter adjustments */ --ap; --d__; --e; u_dim1 = *ldu; u_offset = 1 + u_dim1; u -= u_offset; --vp; --tau; --work; --rwork; --result; /* Function Body */ result[1] = 0.f; if (*itype == 1) { result[2] = 0.f; } if (*n <= 0) { return 0; } lap = *n * (*n + 1) / 2; if (lsame_(uplo, "U")) { lower = FALSE_; *(unsigned char *)cuplo = 'U'; } else { lower = TRUE_; *(unsigned char *)cuplo = 'L'; } unfl = slamch_("Safe minimum"); ulp = slamch_("Epsilon") * slamch_("Base"); /* Some Error Checks */ if (*itype < 1 || *itype > 3) { result[1] = 10.f / ulp; return 0; } /* Do Test 1 Norm of A: */ if (*itype == 3) { anorm = 1.f; } else { /* Computing MAX */ r__1 = clanhp_("1", cuplo, n, &ap[1], &rwork[1]) ; anorm = dmax(r__1,unfl); } /* Compute error matrix: */ if (*itype == 1) { /* ITYPE=1: error = A - U S U* */ claset_("Full", n, n, &c_b1, &c_b1, &work[1], n); ccopy_(&lap, &ap[1], &c__1, &work[1], &c__1); i__1 = *n; for (j = 1; j <= i__1; ++j) { r__1 = -d__[j]; chpr_(cuplo, n, &r__1, &u[j * u_dim1 + 1], &c__1, &work[1]); /* L10: */ } if (*n > 1 && *kband == 1) { i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { i__2 = j; q__2.r = e[i__2], q__2.i = 0.f; q__1.r = -q__2.r, q__1.i = -q__2.i; chpr2_(cuplo, n, &q__1, &u[j * u_dim1 + 1], &c__1, &u[(j - 1) * u_dim1 + 1], &c__1, &work[1]); /* L20: */ } } wnorm = clanhp_("1", cuplo, n, &work[1], &rwork[1]); } else if (*itype == 2) { /* ITYPE=2: error = V S V* - A */ claset_("Full", n, n, &c_b1, &c_b1, &work[1], n); if (lower) { i__1 = lap; i__2 = *n; work[i__1].r = d__[i__2], work[i__1].i = 0.f; for (j = *n - 1; j >= 1; --j) { jp = ((*n << 1) - j) * (j - 1) / 2; jp1 = jp + *n - j; if (*kband == 1) { i__1 = jp + j + 1; i__2 = j; q__2.r = 1.f - tau[i__2].r, q__2.i = 0.f - tau[i__2].i; i__3 = j; q__1.r = e[i__3] * q__2.r, q__1.i = e[i__3] * q__2.i; work[i__1].r = q__1.r, work[i__1].i = q__1.i; i__1 = *n; for (jr = j + 2; jr <= i__1; ++jr) { i__2 = jp + jr; i__3 = j; q__3.r = -tau[i__3].r, q__3.i = -tau[i__3].i; i__4 = j; q__2.r = e[i__4] * q__3.r, q__2.i = e[i__4] * q__3.i; i__5 = jp + jr; q__1.r = q__2.r * vp[i__5].r - q__2.i * vp[i__5].i, q__1.i = q__2.r * vp[i__5].i + q__2.i * vp[ i__5].r; work[i__2].r = q__1.r, work[i__2].i = q__1.i; /* L30: */ } } i__1 = j; if (tau[i__1].r != 0.f || tau[i__1].i != 0.f) { i__1 = jp + j + 1; vsave.r = vp[i__1].r, vsave.i = vp[i__1].i; i__1 = jp + j + 1; vp[i__1].r = 1.f, vp[i__1].i = 0.f; i__1 = *n - j; chpmv_("L", &i__1, &c_b2, &work[jp1 + j + 1], &vp[jp + j + 1], &c__1, &c_b1, &work[lap + 1], &c__1); i__1 = j; q__2.r = tau[i__1].r * -.5f, q__2.i = tau[i__1].i * -.5f; i__2 = *n - j; cdotc_(&q__3, &i__2, &work[lap + 1], &c__1, &vp[jp + j + 1], &c__1); q__1.r = q__2.r * q__3.r - q__2.i * q__3.i, q__1.i = q__2.r * q__3.i + q__2.i * q__3.r; temp.r = q__1.r, temp.i = q__1.i; i__1 = *n - j; caxpy_(&i__1, &temp, &vp[jp + j + 1], &c__1, &work[lap + 1], &c__1); i__1 = *n - j; i__2 = j; q__1.r = -tau[i__2].r, q__1.i = -tau[i__2].i; chpr2_("L", &i__1, &q__1, &vp[jp + j + 1], &c__1, &work[ lap + 1], &c__1, &work[jp1 + j + 1]); i__1 = jp + j + 1; vp[i__1].r = vsave.r, vp[i__1].i = vsave.i; } i__1 = jp + j; i__2 = j; work[i__1].r = d__[i__2], work[i__1].i = 0.f; /* L40: */ } } else { work[1].r = d__[1], work[1].i = 0.f; i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { jp = j * (j - 1) / 2; jp1 = jp + j; if (*kband == 1) { i__2 = jp1 + j; i__3 = j; q__2.r = 1.f - tau[i__3].r, q__2.i = 0.f - tau[i__3].i; i__4 = j; q__1.r = e[i__4] * q__2.r, q__1.i = e[i__4] * q__2.i; work[i__2].r = q__1.r, work[i__2].i = q__1.i; i__2 = j - 1; for (jr = 1; jr <= i__2; ++jr) { i__3 = jp1 + jr; i__4 = j; q__3.r = -tau[i__4].r, q__3.i = -tau[i__4].i; i__5 = j; q__2.r = e[i__5] * q__3.r, q__2.i = e[i__5] * q__3.i; i__6 = jp1 + jr; q__1.r = q__2.r * vp[i__6].r - q__2.i * vp[i__6].i, q__1.i = q__2.r * vp[i__6].i + q__2.i * vp[ i__6].r; work[i__3].r = q__1.r, work[i__3].i = q__1.i; /* L50: */ } } i__2 = j; if (tau[i__2].r != 0.f || tau[i__2].i != 0.f) { i__2 = jp1 + j; vsave.r = vp[i__2].r, vsave.i = vp[i__2].i; i__2 = jp1 + j; vp[i__2].r = 1.f, vp[i__2].i = 0.f; chpmv_("U", &j, &c_b2, &work[1], &vp[jp1 + 1], &c__1, & c_b1, &work[lap + 1], &c__1); i__2 = j; q__2.r = tau[i__2].r * -.5f, q__2.i = tau[i__2].i * -.5f; cdotc_(&q__3, &j, &work[lap + 1], &c__1, &vp[jp1 + 1], & c__1); q__1.r = q__2.r * q__3.r - q__2.i * q__3.i, q__1.i = q__2.r * q__3.i + q__2.i * q__3.r; temp.r = q__1.r, temp.i = q__1.i; caxpy_(&j, &temp, &vp[jp1 + 1], &c__1, &work[lap + 1], & c__1); i__2 = j; q__1.r = -tau[i__2].r, q__1.i = -tau[i__2].i; chpr2_("U", &j, &q__1, &vp[jp1 + 1], &c__1, &work[lap + 1] , &c__1, &work[1]); i__2 = jp1 + j; vp[i__2].r = vsave.r, vp[i__2].i = vsave.i; } i__2 = jp1 + j + 1; i__3 = j + 1; work[i__2].r = d__[i__3], work[i__2].i = 0.f; /* L60: */ } } i__1 = lap; for (j = 1; j <= i__1; ++j) { i__2 = j; i__3 = j; i__4 = j; q__1.r = work[i__3].r - ap[i__4].r, q__1.i = work[i__3].i - ap[ i__4].i; work[i__2].r = q__1.r, work[i__2].i = q__1.i; /* L70: */ } wnorm = clanhp_("1", cuplo, n, &work[1], &rwork[1]); } else if (*itype == 3) { /* ITYPE=3: error = U V* - I */ if (*n < 2) { return 0; } clacpy_(" ", n, n, &u[u_offset], ldu, &work[1], n); /* Computing 2nd power */ i__1 = *n; cupmtr_("R", cuplo, "C", n, n, &vp[1], &tau[1], &work[1], n, &work[ i__1 * i__1 + 1], &iinfo); if (iinfo != 0) { result[1] = 10.f / ulp; return 0; } i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = (*n + 1) * (j - 1) + 1; i__3 = (*n + 1) * (j - 1) + 1; q__1.r = work[i__3].r - 1.f, q__1.i = work[i__3].i - 0.f; work[i__2].r = q__1.r, work[i__2].i = q__1.i; /* L80: */ } wnorm = clange_("1", n, n, &work[1], n, &rwork[1]); } if (anorm > wnorm) { result[1] = wnorm / anorm / (*n * ulp); } else { if (anorm < 1.f) { /* Computing MIN */ r__1 = wnorm, r__2 = *n * anorm; result[1] = dmin(r__1,r__2) / anorm / (*n * ulp); } else { /* Computing MIN */ r__1 = wnorm / anorm, r__2 = (real) (*n); result[1] = dmin(r__1,r__2) / (*n * ulp); } } /* Do Test 2 Compute UU* - I */ if (*itype == 1) { cgemm_("N", "C", n, n, n, &c_b2, &u[u_offset], ldu, &u[u_offset], ldu, &c_b1, &work[1], n); i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = (*n + 1) * (j - 1) + 1; i__3 = (*n + 1) * (j - 1) + 1; q__1.r = work[i__3].r - 1.f, q__1.i = work[i__3].i - 0.f; work[i__2].r = q__1.r, work[i__2].i = q__1.i; /* L90: */ } /* Computing MIN */ r__1 = clange_("1", n, n, &work[1], n, &rwork[1]), r__2 = ( real) (*n); result[2] = dmin(r__1,r__2) / (*n * ulp); } return 0; /* End of CHPT21 */ } /* chpt21_ */