[ новости /+++ | форум | теги | ]

NAME
     slatzm - apply a Householder matrix generated by STZRQF to a
     matrix

SYNOPSIS
     SUBROUTINE SLATZM( SIDE, M, N, V, INCV, TAU,  C1,  C2,  LDC,
               WORK )

     CHARACTER SIDE

     INTEGER INCV, LDC, M, N

     REAL TAU

     REAL C1( LDC, * ), C2( LDC, * ), V( * ), WORK( * )



     #include <sunperf.h>

     void slatzm(char side, int m, int n,  float  *v,  int  incv,
               float tau, float *c1, float *c2, int ldc) ;

PURPOSE
     SLATZM applies a Householder matrix generated by STZRQF to a
     matrix.

     Let P = I - tau*u*u',   u = ( 1 ),
                                 ( v )
     where v is an (m-1) vector if SIDE = 'L', or a (n-1)  vector
     if SIDE = 'R'.

     If SIDE equals 'L', let
            C = [ C1 ] 1
                [ C2 ] m-1
                  n
     Then C is overwritten by P*C.

     If SIDE equals 'R', let
            C = [ C1, C2 ] m
                   1  n-1
     Then C is overwritten by C*P.


ARGUMENTS
     SIDE      (input) CHARACTER*1
               = 'L': form P * C
               = 'R': form C * P

     M         (input) INTEGER
               The number of rows of the matrix C.

     N         (input) INTEGER
               The number of columns of the matrix C.

     V         (input) REAL array, dimension
               (1 + (M-1)*abs(INCV)) if  SIDE  =  'L'  (1  +  (N-
               1)*abs(INCV))  if  SIDE  = 'R' The vector v in the
               representation of P. V is not used if TAU = 0.

     INCV      (input) INTEGER
               The increment between elements of v. INCV <> 0

     TAU       (input) REAL
               The value tau in the representation of P.

     C1        (input/output) REAL array, dimension
               (LDC,N) if SIDE = 'L' (M,1)   if  SIDE  =  'R'  On
               entry,  the  n-vector  C1 if SIDE = 'L', or the m-
               vector C1 if SIDE = 'R'.

               On exit, the first row of P*C if SIDE  =  'L',  or
               the first column of C*P if SIDE = 'R'.

     C2        (input/output) REAL array, dimension
               (LDC, N)   if SIDE = 'L' (LDC, N-1) if SIDE =  'R'
               On entry, the (m - 1) x n matrix C2 if SIDE = 'L',
               or the m x (n - 1) matrix C2 if SIDE = 'R'.

               On exit, rows 2:m of P*C if SIDE = 'L', or columns
               2:m of C*P if SIDE = 'R'.

     LDC       (input) INTEGER
               The leading dimension of the arrays C1 and C2. LDC
               >= (1,M).

     WORK      (workspace) REAL array, dimension
               (N) if SIDE = 'L' (M) if SIDE = 'R'

Партнёры:

Хостинг: