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Functions | |
int | dorg2r_fla (integer *m, integer *n, integer *k, doublereal *a, integer *lda, doublereal *tau, doublereal *work, integer *info) |
int dorg2r_fla | ( | integer * | m, |
integer * | n, | ||
integer * | k, | ||
doublereal * | a, | ||
integer * | lda, | ||
doublereal * | tau, | ||
doublereal * | work, | ||
integer * | info | ||
) |
Referenced by dopgtr_(), and dorgqr_fla().
{ /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; doublereal d__1; /* Local variables */ integer i__, j, l; extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, integer *), dlarf_(char *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, doublereal *), xerbla_(char *, integer *); /* -- LAPACK computational routine (version 3.4.2) -- */ /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */ /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */ /* September 2012 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < 0 || *n > *m) { *info = -2; } else if (*k < 0 || *k > *n) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } if (*info != 0) { i__1 = -(*info); xerbla_("DORG2R", &i__1); return 0; } /* Quick return if possible */ if (*n <= 0) { return 0; } /* Initialise columns k+1:n to columns of the unit matrix */ i__1 = *n; for (j = *k + 1; j <= i__1; ++j) { i__2 = *m; for (l = 1; l <= i__2; ++l) { a[l + j * a_dim1] = 0.; /* L10: */ } a[j + j * a_dim1] = 1.; /* L20: */ } for (i__ = *k; i__ >= 1; --i__) { /* Apply H(i) to A(i:m,i:n) from the left */ if (i__ < *n) { a[i__ + i__ * a_dim1] = 1.; i__1 = *m - i__ + 1; i__2 = *n - i__; dlarf_("Left", &i__1, &i__2, &a[i__ + i__ * a_dim1], &c__1, &tau[ i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[1]); } if (i__ < *m) { i__1 = *m - i__; d__1 = -tau[i__]; dscal_(&i__1, &d__1, &a[i__ + 1 + i__ * a_dim1], &c__1); } a[i__ + i__ * a_dim1] = 1. - tau[i__]; /* Set A(1:i-1,i) to zero */ i__1 = i__ - 1; for (l = 1; l <= i__1; ++l) { a[l + i__ * a_dim1] = 0.; /* L30: */ } /* L40: */ } return 0; /* End of DORG2R */ }