zlagtm (3) - Linux Man Pages

NAME

zlagtm.f -

SYNOPSIS


Functions/Subroutines


subroutine zlagtm (TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA, B, LDB)
ZLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix, B and C are rectangular matrices, and α and β are scalars, which may be 0, 1, or -1.

Function/Subroutine Documentation

subroutine zlagtm (characterTRANS, integerN, integerNRHS, double precisionALPHA, complex*16, dimension( * )DL, complex*16, dimension( * )D, complex*16, dimension( * )DU, complex*16, dimension( ldx, * )X, integerLDX, double precisionBETA, complex*16, dimension( ldb, * )B, integerLDB)

ZLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix, B and C are rectangular matrices, and α and β are scalars, which may be 0, 1, or -1.

Purpose:

 ZLAGTM performs a matrix-vector product of the form

    B := alpha * A * X + beta * B

 where A is a tridiagonal matrix of order N, B and X are N by NRHS
 matrices, and alpha and beta are real scalars, each of which may be
 0., 1., or -1.


 

Parameters:

TRANS

          TRANS is CHARACTER*1
          Specifies the operation applied to A.
          = 'N':  No transpose, B := alpha * A * X + beta * B
          = 'T':  Transpose,    B := alpha * A**T * X + beta * B
          = 'C':  Conjugate transpose, B := alpha * A**H * X + beta * B


N

          N is INTEGER
          The order of the matrix A.  N >= 0.


NRHS

          NRHS is INTEGER
          The number of right hand sides, i.e., the number of columns
          of the matrices X and B.


ALPHA

          ALPHA is DOUBLE PRECISION
          The scalar alpha.  ALPHA must be 0., 1., or -1.; otherwise,
          it is assumed to be 0.


DL

          DL is COMPLEX*16 array, dimension (N-1)
          The (n-1) sub-diagonal elements of T.


D

          D is COMPLEX*16 array, dimension (N)
          The diagonal elements of T.


DU

          DU is COMPLEX*16 array, dimension (N-1)
          The (n-1) super-diagonal elements of T.


X

          X is COMPLEX*16 array, dimension (LDX,NRHS)
          The N by NRHS matrix X.


LDX

          LDX is INTEGER
          The leading dimension of the array X.  LDX >= max(N,1).


BETA

          BETA is DOUBLE PRECISION
          The scalar beta.  BETA must be 0., 1., or -1.; otherwise,
          it is assumed to be 1.


B

          B is COMPLEX*16 array, dimension (LDB,NRHS)
          On entry, the N by NRHS matrix B.
          On exit, B is overwritten by the matrix expression
          B := alpha * A * X + beta * B.


LDB

          LDB is INTEGER
          The leading dimension of the array B.  LDB >= max(N,1).


 

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 145 of file zlagtm.f.

Author

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