dlat2s (l) - Linux Manuals

dlat2s: converts a DOUBLE PRECISION triangular matrix, SA, to a SINGLE PRECISION triangular matrix, A

NAME

DLAT2S - converts a DOUBLE PRECISION triangular matrix, SA, to a SINGLE PRECISION triangular matrix, A

SYNOPSIS

SUBROUTINE DLAT2S(
UPLO, N, A, LDA, SA, LDSA, INFO )

    
CHARACTER UPLO

    
INTEGER INFO, LDA, LDSA, N

    
REAL SA( LDSA, * )

    
DOUBLE PRECISION A( LDA, * )

PURPOSE

DLAT2S converts a DOUBLE PRECISION triangular matrix, SA, to a SINGLE PRECISION triangular matrix, A. RMAX is the overflow for the SINGLE PRECISION arithmetic
DLAS2S checks that all the entries of A are between -RMAX and RMAX. If not the convertion is aborted and a flag is raised. This is an auxiliary routine so there is no argument checking.

ARGUMENTS

UPLO (input) CHARACTER*1
= aqUaq: A is upper triangular;
= aqLaq: A is lower triangular.
N (input) INTEGER
The number of rows and columns of the matrix A. N >= 0.
A (input) DOUBLE PRECISION array, dimension (LDA,N)
On entry, the N-by-N triangular coefficient matrix A.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
SA (output) REAL array, dimension (LDSA,N)
Only the UPLO part of SA is referenced. On exit, if INFO=0, the N-by-N coefficient matrix SA; if INFO>0, the content of the UPLO part of SA is unspecified.
LDSA (input) INTEGER
The leading dimension of the array SA. LDSA >= max(1,M).
INFO (output) INTEGER
= 0: successful exit.
= 1: an entry of the matrix A is greater than the SINGLE PRECISION overflow threshold, in this case, the content of the UPLO part of SA in exit is unspecified. ========= End of DLAT2S

Pages related to dlat2s

  • dlat2s (3)
  • dlatbs (l) - solves one of the triangular systems A *x = s*b or Aaq*x = s*b with scaling to prevent overflow, where A is an upper or lower triangular band matrix
  • dlatdf (l) - uses the LU factorization of the n-by-n matrix Z computed by DGETC2 and computes a contribution to the reciprocal Dif-estimate by solving Z * x = b for x, and choosing the r.h.s
  • dlatps (l) - solves one of the triangular systems A *x = s*b or Aaq*x = s*b with scaling to prevent overflow, where A is an upper or lower triangular matrix stored in packed form
  • dlatrd (l) - reduces NB rows and columns of a real symmetric matrix A to symmetric tridiagonal form by an orthogonal similarity transformation Qaq * A * Q, and returns the matrices V and W which are needed to apply the transformation to the unreduced part of A
  • dlatrs (l) - solves one of the triangular systems A *x = s*b or Aaq*x = s*b with scaling to prevent overflow
  • dlatrz (l) - factors the M-by-(M+L) real upper trapezoidal matrix [ A1 A2 ] = [ A(1:M,1:M) A(1:M,N-L+1:N) ] as ( R 0 ) * Z, by means of orthogonal transformations
  • dlatzm (l) - routine i deprecated and has been replaced by routine DORMRZ
  • dla_gbamv (l) - performs one of the matrix-vector operations y := alpha*abs(A)*abs(x) + beta*abs(y),