#include "f2c.h" /* Subroutine */ int dlaset_(char *uplo, integer *m, integer *n, doublereal * alpha, doublereal *beta, doublereal *a, integer *lda) { /* -- LAPACK auxiliary routine (version 2.0) -- Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., Courant Institute, Argonne National Lab, and Rice University October 31, 1992 Purpose ======= DLASET initializes an m-by-n matrix A to BETA on the diagonal and ALPHA on the offdiagonals. Arguments ========= UPLO (input) CHARACTER*1 Specifies the part of the matrix A to be set. = 'U': Upper triangular part is set; the strictly lower triangular part of A is not changed. = 'L': Lower triangular part is set; the strictly upper triangular part of A is not changed. Otherwise: All of the matrix A is set. M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. ALPHA (input) DOUBLE PRECISION The constant to which the offdiagonal elements are to be set. BETA (input) DOUBLE PRECISION The constant to which the diagonal elements are to be set. A (input/output) DOUBLE PRECISION array, dimension (LDA,N) On exit, the leading m-by-n submatrix of A is set as follows: if UPLO = 'U', A(i,j) = ALPHA, 1<=i<=j-1, 1<=j<=n, if UPLO = 'L', A(i,j) = ALPHA, j+1<=i<=m, 1<=j<=n, otherwise, A(i,j) = ALPHA, 1<=i<=m, 1<=j<=n, i.ne.j, and, for all UPLO, A(i,i) = BETA, 1<=i<=min(m,n). LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). ===================================================================== Function Body */ /* System generated locals */ integer i__1, i__2, i__3; /* Local variables */ static integer i, j; extern logical lsame_(char *, char *); #define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)] if (lsame_(uplo, "U")) { /* Set the strictly upper triangular or trapezoidal part of the array to ALPHA. */ i__1 = *n; for (j = 2; j <= *n; ++j) { /* Computing MIN */ i__3 = j - 1; i__2 = min(i__3,*m); for (i = 1; i <= min(j-1,*m); ++i) { A(i,j) = *alpha; /* L10: */ } /* L20: */ } } else if (lsame_(uplo, "L")) { /* Set the strictly lower triangular or trapezoidal part of the array to ALPHA. */ i__1 = min(*m,*n); for (j = 1; j <= min(*m,*n); ++j) { i__2 = *m; for (i = j + 1; i <= *m; ++i) { A(i,j) = *alpha; /* L30: */ } /* L40: */ } } else { /* Set the leading m-by-n submatrix to ALPHA. */ i__1 = *n; for (j = 1; j <= *n; ++j) { i__2 = *m; for (i = 1; i <= *m; ++i) { A(i,j) = *alpha; /* L50: */ } /* L60: */ } } /* Set the first min(M,N) diagonal elements to BETA. */ i__1 = min(*m,*n); for (i = 1; i <= min(*m,*n); ++i) { A(i,i) = *beta; /* L70: */ } return 0; /* End of DLASET */ } /* dlaset_ */