ctptrs.f (3) - Linux Man Pages

NAME

ctptrs.f -

SYNOPSIS


Functions/Subroutines


subroutine ctptrs (UPLO, TRANS, DIAG, N, NRHS, AP, B, LDB, INFO)
CTPTRS

Function/Subroutine Documentation

subroutine ctptrs (characterUPLO, characterTRANS, characterDIAG, integerN, integerNRHS, complex, dimension( * )AP, complex, dimension( ldb, * )B, integerLDB, integerINFO)

CTPTRS

Purpose:

 CTPTRS solves a triangular system of the form

    A * X = B,  A**T * X = B,  or  A**H * X = B,

 where A is a triangular matrix of order N stored in packed format,
 and B is an N-by-NRHS matrix.  A check is made to verify that A is
 nonsingular.


 

Parameters:

UPLO

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


TRANS

          TRANS is CHARACTER*1
          Specifies the form of the system of equations:
          = 'N':  A * X = B     (No transpose)
          = 'T':  A**T * X = B  (Transpose)
          = 'C':  A**H * X = B  (Conjugate transpose)


DIAG

          DIAG is CHARACTER*1
          = 'N':  A is non-unit triangular;
          = 'U':  A is unit triangular.


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 matrix B.  NRHS >= 0.


AP

          AP is COMPLEX array, dimension (N*(N+1)/2)
          The upper or lower triangular matrix A, packed columnwise in
          a linear array.  The j-th column of A is stored in the array
          AP as follows:
          if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
          if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.


B

          B is COMPLEX array, dimension (LDB,NRHS)
          On entry, the right hand side matrix B.
          On exit, if INFO = 0, the solution matrix X.


LDB

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


INFO

          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
          > 0:  if INFO = i, the i-th diagonal element of A is zero,
                indicating that the matrix is singular and the
                solutions X have not been computed.


 

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Definition at line 131 of file ctptrs.f.

Author

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