#include "blaswrap.h" #include "f2c.h" /* Subroutine */ int cupmtr_(char *side, char *uplo, char *trans, integer *m, integer *n, complex *ap, complex *tau, complex *c__, integer *ldc, complex *work, integer *info) { /* -- LAPACK routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 Purpose ======= CUPMTR overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C': Q**H * C C * Q**H where Q is a complex unitary matrix of order nq, with nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of nq-1 elementary reflectors, as returned by CHPTRD using packed storage: if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1); if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1). Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q**H from the Left; = 'R': apply Q or Q**H from the Right. UPLO (input) CHARACTER*1 = 'U': Upper triangular packed storage used in previous call to CHPTRD; = 'L': Lower triangular packed storage used in previous call to CHPTRD. TRANS (input) CHARACTER*1 = 'N': No transpose, apply Q; = 'C': Conjugate transpose, apply Q**H. M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. AP (input) COMPLEX array, dimension (M*(M+1)/2) if SIDE = 'L' (N*(N+1)/2) if SIDE = 'R' The vectors which define the elementary reflectors, as returned by CHPTRD. AP is modified by the routine but restored on exit. TAU (input) COMPLEX array, dimension (M-1) if SIDE = 'L' or (N-1) if SIDE = 'R' TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CHPTRD. C (input/output) COMPLEX array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) COMPLEX array, dimension (N) if SIDE = 'L' (M) if SIDE = 'R' INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments Parameter adjustments */ /* Table of constant values */ static integer c__1 = 1; /* System generated locals */ integer c_dim1, c_offset, i__1, i__2, i__3; complex q__1; /* Builtin functions */ void r_cnjg(complex *, complex *); /* Local variables */ static integer i__, i1, i2, i3, ic, jc, ii, mi, ni, nq; static complex aii; static logical left; static complex taui; extern /* Subroutine */ int clarf_(char *, integer *, integer *, complex * , integer *, complex *, complex *, integer *, complex *); extern logical lsame_(char *, char *); static logical upper; extern /* Subroutine */ int xerbla_(char *, integer *); static logical notran, forwrd; --ap; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); upper = lsame_(uplo, "U"); /* NQ is the order of Q */ if (left) { nq = *m; } else { nq = *n; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! upper && ! lsame_(uplo, "L")) { *info = -2; } else if (! notran && ! lsame_(trans, "C")) { *info = -3; } else if (*m < 0) { *info = -4; } else if (*n < 0) { *info = -5; } else if (*ldc < max(1,*m)) { *info = -9; } if (*info != 0) { i__1 = -(*info); xerbla_("CUPMTR", &i__1); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } if (upper) { /* Q was determined by a call to CHPTRD with UPLO = 'U' */ forwrd = left && notran || ! left && ! notran; if (forwrd) { i1 = 1; i2 = nq - 1; i3 = 1; ii = 2; } else { i1 = nq - 1; i2 = 1; i3 = -1; ii = nq * (nq + 1) / 2 - 1; } if (left) { ni = *n; } else { mi = *m; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { if (left) { /* H(i) or H(i)' is applied to C(1:i,1:n) */ mi = i__; } else { /* H(i) or H(i)' is applied to C(1:m,1:i) */ ni = i__; } /* Apply H(i) or H(i)' */ if (notran) { i__3 = i__; taui.r = tau[i__3].r, taui.i = tau[i__3].i; } else { r_cnjg(&q__1, &tau[i__]); taui.r = q__1.r, taui.i = q__1.i; } i__3 = ii; aii.r = ap[i__3].r, aii.i = ap[i__3].i; i__3 = ii; ap[i__3].r = 1.f, ap[i__3].i = 0.f; clarf_(side, &mi, &ni, &ap[ii - i__ + 1], &c__1, &taui, &c__[ c_offset], ldc, &work[1]); i__3 = ii; ap[i__3].r = aii.r, ap[i__3].i = aii.i; if (forwrd) { ii = ii + i__ + 2; } else { ii = ii - i__ - 1; } /* L10: */ } } else { /* Q was determined by a call to CHPTRD with UPLO = 'L'. */ forwrd = left && ! notran || ! left && notran; if (forwrd) { i1 = 1; i2 = nq - 1; i3 = 1; ii = 2; } else { i1 = nq - 1; i2 = 1; i3 = -1; ii = nq * (nq + 1) / 2 - 1; } if (left) { ni = *n; jc = 1; } else { mi = *m; ic = 1; } i__2 = i2; i__1 = i3; for (i__ = i1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { i__3 = ii; aii.r = ap[i__3].r, aii.i = ap[i__3].i; i__3 = ii; ap[i__3].r = 1.f, ap[i__3].i = 0.f; if (left) { /* H(i) or H(i)' is applied to C(i+1:m,1:n) */ mi = *m - i__; ic = i__ + 1; } else { /* H(i) or H(i)' is applied to C(1:m,i+1:n) */ ni = *n - i__; jc = i__ + 1; } /* Apply H(i) or H(i)' */ if (notran) { i__3 = i__; taui.r = tau[i__3].r, taui.i = tau[i__3].i; } else { r_cnjg(&q__1, &tau[i__]); taui.r = q__1.r, taui.i = q__1.i; } clarf_(side, &mi, &ni, &ap[ii], &c__1, &taui, &c__[ic + jc * c_dim1], ldc, &work[1]); i__3 = ii; ap[i__3].r = aii.r, ap[i__3].i = aii.i; if (forwrd) { ii = ii + nq - i__ + 1; } else { ii = ii - nq + i__ - 2; } /* L20: */ } } return 0; /* End of CUPMTR */ } /* cupmtr_ */