?tftri
?tftri
Computes the inverse of a triangular matrix stored in the Rectangular Full Packed (RFP) format.
Syntax
lapack_int
LAPACKE_stftri
(
int
matrix_layout
,
char
transr
,
char
uplo
,
char
diag
,
lapack_int
n
,
float
*
a
);
lapack_int
LAPACKE_dtftri
(
int
matrix_layout
,
char
transr
,
char
uplo
,
char
diag
,
lapack_int
n
,
double
*
a
);
lapack_int
LAPACKE_ctftri
(
int
matrix_layout
,
char
transr
,
char
uplo
,
char
diag
,
lapack_int
n
,
lapack_complex_float
*
a
);
lapack_int
LAPACKE_ztftri
(
int
matrix_layout
,
char
transr
,
char
uplo
,
char
diag
,
lapack_int
n
,
lapack_complex_double
*
a
);
Include Files
- mkl.h
Description
Computes the inverse of a triangular matrix
A
stored in the Rectangular Full Packed (RFP) format. For the description of the RFP format, see Matrix Storage Schemes.This is the block version of the algorithm, calling Level 3 BLAS.
Input Parameters
- matrix_layout
- Specifies whether matrix storage layout is row major (LAPACK_ROW_MAJOR) or column major (LAPACK_COL_MAJOR).
- transr
- Must be'N','T'(for real data) or'C'(for complex data).Iftransr='N', the Normaltransrof RFPAis stored.Iftransr='T', the Transposetransrof RFPAis stored.Iftransr='C', the Conjugate-Transposetransrof RFPAis stored.
- uplo
- Must be'U'or'L'.Indicates whether the upper or lower triangular part of RFPAis stored:Ifuplo='U', the arrayastores the upper triangular part of the matrixA.Ifuplo='L', the arrayastores the lower triangular part of the matrixA.
- diag
- Must be'N'or'U'.If, thendiag='N'Ais not a unit triangular matrix.If,diag='U'Ais unit triangular: diagonal elements ofAare assumed to be 1 and not referenced in the arraya.
- n
- The order of the matrixA;n≥0.
- a
- Array, size max(1,n*(n+ 1)/2). The arrayacontains the matrixAin the RFP format.
Output Parameters
- a
- The (triangular) inverse of the original matrix in the same storage format.
Return Values
This function returns a value
info
.If , the execution is successful.
info
=0If , parameter
info
= -i
i
had an illegal value.If , is exactly zero.
The triangular matrix is singular and its inverse cannot be
computed.
info
= i
A
i
, i