# dtrttp.f - Man Page

SRC/dtrttp.f

## Synopsis

### Functions/Subroutines

subroutine **dtrttp** (uplo, n, a, lda, ap, info)**DTRTTP** copies a triangular matrix from the standard full format (TR) to the standard packed format (TP).

## Function/Subroutine Documentation

### subroutine dtrttp (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) ap, integer info)

**DTRTTP** copies a triangular matrix from the standard full format (TR) to the standard packed format (TP).

**Purpose:**

DTRTTP copies a triangular matrix A from full format (TR) to standard packed format (TP).

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

*N*N is INTEGER The order of the matrices AP and A. N >= 0.

*A*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 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 A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced.

*LDA*LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N).

*AP*AP is DOUBLE PRECISION array, dimension (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*INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value

**Author**Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **103** of file **dtrttp.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dtrttp(3) is an alias of dtrttp.f(3).

Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK