?trttp

Syntax

FORTRAN 77:

call strttp( uplo, n, a, lda, ap, info )

call dtrttp( uplo, n, a, lda, ap, info )

call ctrttp( uplo, n, a, lda, ap, info )

call ztrttp( uplo, n, a, lda, ap, info )

C:

lapack_int LAPACKE_<?>trttp( int matrix_order, char uplo, lapack_int n, const <datatype>* a, lapack_int lda, <datatype>* ap );

Include Files

The FORTRAN 77 interfaces are specified in the mkl_lapack.fi and mkl_lapack.h include files and the C interfaces are specified in the mkl_lapacke.h include file.

Description

The routine copies a triangular matrix A from the standard full format to the standard packed format.

Input Parameters

The data types are given for the Fortran interface. A <datatype> placeholder, if present, is used for the C interface data types in the C interface section above. See C Interface Conventions for the C interface principal conventions and type defintions.

uplo

CHARACTER*1.

Specifies whether A is upper or lower triangular:

= 'U': A is upper triangular,

= 'L': A is lower triangular.

n

INTEGER. The order of the matrices a and ap. n ≥ 0.

a

REAL for strttp,

DOUBLE PRECISION for dtrttp,

COMPLEX for ctrttp,

DOUBLE COMPLEX for ztrttp.

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

INTEGER. The leading dimension of the array a. lda ≥ max(1,n).

Output Parameters

ap

REAL for strttp,

DOUBLE PRECISION for dtrttp,

COMPLEX for ctrttp,

DOUBLE COMPLEX for ztrttp.

Array, DIMENSION at least max (1, n*(n+1)/2).

On exit, 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)*(2n-j)/2) = A(i,j) for j ≤ i ≤ n.

info

INTEGER.

=0: successful exit,

< 0: if info = -i, the i-th parameter had an illegal value.