# ?tpttr

Copies a triangular matrix from the standard packed format (TP) to the standard full format (TR) .

## Syntax

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

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

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

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

• mkl.fi

## Description

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

## Input Parameters

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 ap and a. `n ≥ 0`.

ap

REAL for stpttr,

DOUBLE PRECISION for dtpttr,

COMPLEX for ctpttr,

DOUBLE COMPLEX for ztpttr.

On entry, 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.

lda

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

## Output Parameters

a

REAL for stpttr,

DOUBLE PRECISION for dtpttr,

COMPLEX for ctpttr,

DOUBLE COMPLEX for ztpttr.

Array, size (lda, *).

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 part of the matrix A, 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 part of the matrix A, and the strictly upper triangular part of a is not referenced.

info

INTEGER.

If `info = 0`, the execution is successful.

If `info = -i`, the i-th parameter had an illegal value.

If `info = -1011`, memory allocation error occurred.

For more complete information about compiler optimizations, see our Optimization Notice.