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Updated: June 2017
 
 

dtfttr (3p)

Name

dtfttr - mat (TF) to the standard full format (TR)

Synopsis

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


CHARACTER*1 TRANSR, UPLO

INTEGER INFO, N, LDA

DOUBLE PRECISION A(0:LDA-1,0:*), ARF(0:*)


SUBROUTINE DTFTTR_64(TRANSR, UPLO, N, ARF, A, LDA, INFO)


CHARACTER*1 TRANSR, UPLO

INTEGER*8 INFO, N, LDA

DOUBLE PRECISION A(0:LDA-1,0:*), ARF(0:*)


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


INTEGER :: N, LDA, INFO

CHARACTER(LEN=1) :: TRANSR, UPLO

REAL(8), DIMENSION(:,:) :: A

REAL(8), DIMENSION(:) :: ARF


SUBROUTINE TFTTR_64(TRANSR, UPLO, N, ARF, A, LDA, INFO)


INTEGER(8) :: N, LDA, INFO

CHARACTER(LEN=1) :: TRANSR, UPLO

REAL(8), DIMENSION(:,:) :: A

REAL(8), DIMENSION(:) :: ARF


C INTERFACE
#include <sunperf.h>

void dtfttr (char transr, char uplo, int n, double *arf, double *a, int
lda, int *info);


void dtfttr_64 (char transr, char uplo, long n, double *arf, double *a,
long lda, long *info);

Description

Oracle Solaris Studio Performance Library                           dtfttr(3P)



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


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


       CHARACTER*1 TRANSR, UPLO

       INTEGER INFO, N, LDA

       DOUBLE PRECISION A(0:LDA-1,0:*), ARF(0:*)


       SUBROUTINE DTFTTR_64(TRANSR, UPLO, N, ARF, A, LDA, INFO)


       CHARACTER*1 TRANSR, UPLO

       INTEGER*8 INFO, N, LDA

       DOUBLE PRECISION A(0:LDA-1,0:*), ARF(0:*)


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


       INTEGER :: N, LDA, INFO

       CHARACTER(LEN=1) :: TRANSR, UPLO

       REAL(8), DIMENSION(:,:) :: A

       REAL(8), DIMENSION(:) :: ARF


       SUBROUTINE TFTTR_64(TRANSR, UPLO, N, ARF, A, LDA, INFO)


       INTEGER(8) :: N, LDA, INFO

       CHARACTER(LEN=1) :: TRANSR, UPLO

       REAL(8), DIMENSION(:,:) :: A

       REAL(8), DIMENSION(:) :: ARF


   C INTERFACE
       #include <sunperf.h>

       void dtfttr (char transr, char uplo, int n, double *arf, double *a, int
                 lda, int *info);


       void dtfttr_64 (char transr, char uplo, long n, double *arf, double *a,
                 long lda, long *info);


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


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


       UPLO (input)
                 UPLO is CHARACTER*1
                 = 'U':  A is upper triangular;
                 = 'L':  A is lower triangular.


       N (input)
                 N is INTEGER
                 The order of the matrices ARF and A. N >= 0.


       ARF (input)
                 ARF is DOUBLE PRECISION array, dimension (N*(N+1)/2).
                 On  entry, the upper (if UPLO = 'U') or lower (if UPLO = 'L')
                 matrix A in RFP  format.  See  the  "Notes"  below  for  more
                 details.


       A (output)
                 A is DOUBLE PRECISION array, dimension (LDA,N)
                 On  exit, 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 array A.
                 LDA >= max(1,N).


       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                        dtfttr(3P)