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Updated: June 2017
 
 

strttf (3p)

Name

strttf - copy a triangular matrix from the standard full format (TR) to the rectangular full packed format (TF)

Synopsis

SUBROUTINE STRTTF(TRANSR, UPLO, N, A, LDA, ARF, INFO)


CHARACTER*1 TRANSR, UPLO

INTEGER INFO, N, LDA

REAL A(0:LDA-1,0:*), ARF(0:*)


SUBROUTINE STRTTF_64(TRANSR, UPLO, N, A, LDA, ARF, INFO)


CHARACTER*1 TRANSR, UPLO

INTEGER*8 INFO, N, LDA

REAL A(0:LDA-1,0:*), ARF(0:*)


F95 INTERFACE
SUBROUTINE TRTTF(TRANSR, UPLO, N, A, LDA, ARF, INFO)


REAL, DIMENSION(:,:) :: A

INTEGER :: N, LDA, INFO

CHARACTER(LEN=1) :: TRANSR, UPLO

REAL, DIMENSION(:) :: ARF


SUBROUTINE TRTTF_64(TRANSR, UPLO, N, A, LDA, ARF, INFO)


REAL, DIMENSION(:,:) :: A

INTEGER(8) :: N, LDA, INFO

CHARACTER(LEN=1) :: TRANSR, UPLO

REAL, DIMENSION(:) :: ARF


C INTERFACE
#include <sunperf.h>

void strttf (char transr, char uplo, int n, float *a,  int  lda,  float
*arf, int *info);


void  strttf_64  (char  transr,  char uplo, long n, float *a, long lda,
float *arf, long *info);

Description

Oracle Solaris Studio Performance Library                           strttf(3P)



NAME
       strttf - copy a triangular matrix from the standard full format (TR) to
       the rectangular full packed format (TF)


SYNOPSIS
       SUBROUTINE STRTTF(TRANSR, UPLO, N, A, LDA, ARF, INFO)


       CHARACTER*1 TRANSR, UPLO

       INTEGER INFO, N, LDA

       REAL A(0:LDA-1,0:*), ARF(0:*)


       SUBROUTINE STRTTF_64(TRANSR, UPLO, N, A, LDA, ARF, INFO)


       CHARACTER*1 TRANSR, UPLO

       INTEGER*8 INFO, N, LDA

       REAL A(0:LDA-1,0:*), ARF(0:*)


   F95 INTERFACE
       SUBROUTINE TRTTF(TRANSR, UPLO, N, A, LDA, ARF, INFO)


       REAL, DIMENSION(:,:) :: A

       INTEGER :: N, LDA, INFO

       CHARACTER(LEN=1) :: TRANSR, UPLO

       REAL, DIMENSION(:) :: ARF


       SUBROUTINE TRTTF_64(TRANSR, UPLO, N, A, LDA, ARF, INFO)


       REAL, DIMENSION(:,:) :: A

       INTEGER(8) :: N, LDA, INFO

       CHARACTER(LEN=1) :: TRANSR, UPLO

       REAL, DIMENSION(:) :: ARF


   C INTERFACE
       #include <sunperf.h>

       void strttf (char transr, char uplo, int n, float *a,  int  lda,  float
                 *arf, int *info);


       void  strttf_64  (char  transr,  char uplo, long n, float *a, long lda,
                 float *arf, long *info);


PURPOSE
       strttf copies a triangular matrix A from standard full format  (TR)  to
       rectangular full packed format (TF).


ARGUMENTS
       TRANSR (input)
                 TRANSR is CHARACTER*1
                 = 'N':  ARF in Normal form is wanted;
                 = 'T':  ARF in Transpose form is wanted.


       UPLO (input)
                 UPLO is CHARACTER*1
                 = 'U':  Upper triangle of A is stored;
                 = 'L':  Lower triangle of A is stored.


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


       A (input)
                 A is REAL array, dimension (LDA,N).
                 On entry, the triangular matrix A. If UPLO = 'U', the leading
                 N-by-N upper triangular part of  the  array  A  contains  the
                 upper  triangular  matrix,  and the strictly lower triangular
                 part of A is not referenced. If UPLO = 'L', the leading N-by-
                 N  lower  triangular  part  of the array A contains the lower
                 triangular matrix, and the strictly upper triangular part  of
                 A is not referenced.


       LDA (input)
                 LDA is INTEGER
                 The leading dimension of the matrix A.
                 LDA >= max(1,N).


       ARF (output)
                 ARF is REAL array, dimension (NT).
                 NT=N*(N+1)/2. On exit, the triangular matrix A in RFP format.


       INFO (output)
                 INFO is INTEGER
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument had an illegal value



FURTHER NOTES ON RFP FORMAT
       We first consider Rectangular Full Packed (RFP) Format when N is  even.
       We give an example where N = 6.
         AP is Upper             AP is Lower
       00 01 02 03 04 05       00
          11 12 13 14 15       10 11
             22 23 24 25       20 21 22
                33 34 35       30 31 32 33
                   44 45       40 41 42 43 44
                      55       50 51 52 53 54 55

       Let TRANSR = 'N'. RFP holds AP as follows:
       For  UPLO  =  'U'  the  upper trapezoid A(0:5,0:2) consists of the last
       three columns of AP upper. The lower triangle  A(4:6,0:2)  consists  of
       the transpose of the first three columns of AP upper.
       For  UPLO  =  'L'  the lower trapezoid A(1:6,0:2) consists of the first
       three columns of AP lower. The upper triangle  A(0:2,0:2)  consists  of
       the transpose of the last three columns of AP lower.
       This covers the case N even and TRANSR = 'N'.
              RFP A                   RFP A

             03 04 05                33 43 53
             13 14 15                00 44 54
             23 24 25                10 11 55
             33 34 35                20 21 22
             00 44 45                30 31 32
             01 11 55                40 41 42
             02 12 22                50 51 52

       Now let TRANSR = 'T'. RFP A in both UPLO cases is just the transpose of
       RFP A above. One therefore gets:

                RFP A                   RFP A

       03 13 23 33 00 01 02    33 00 10 20 30 40 50 04 14 24 34 44 11 12    43
       44 11 21 31 41 51 05 15 25 35 45 55 22    53 54 55 22 32 42 52

       We then consider Rectangular Full Packed (RFP) Format when N is odd. We
       give an example where N = 5.

        AP is Upper                 AP is Lower

       00 01 02 03 04              00
          11 12 13 14              10 11
             22 23 24              20 21 22
                33 34              30 31 32 33
                   44              40 41 42 43 44

       Let TRANSR = 'N'. RFP holds AP as follows:
       For UPLO = 'U' the upper trapezoid  A(0:4,0:2)  consists  of  the  last
       three  columns  of  AP upper. The lower triangle A(3:4,0:1) consists of
       the transpose of the first two columns of AP upper.
       For UPLO = 'L' the lower trapezoid A(0:4,0:2)  consists  of  the  first
       three  columns  of  AP lower. The upper triangle A(0:1,1:2) consists of
       the transpose of the last two columns of AP lower.
       This covers the case N odd and TRANSR = 'N'.

              RFP A                   RFP A

             02 03 04                00 33 43
             12 13 14                10 11 44
             22 23 24                20 21 22
             00 33 34                30 31 32
             01 11 44                40 41 42

       Now let TRANSR = 'T'. RFP A in both UPLO cases is just the transpose of
       RFP A above. One therefore gets:

                RFP A                   RFP A

          02 12 22 00 01             00 10 20 30 40 50
          03 13 23 33 11             33 11 21 31 41 51
          04 14 24 34 44             43 44 22 32 42 52



                                  7 Nov 2015                        strttf(3P)