# dtrttp.f man page

dtrttp.f —

## Synopsis

### Functions/Subroutines

subroutinedtrttp(UPLO, N, A, LDA, AP, INFO)DTRTTPcopies a triangular matrix from the standard full format (TR) to the standard packed format (TP).

## Function/Subroutine Documentation

### subroutine dtrttp (characterUPLO, integerN, double precision, dimension( lda, * )A, integerLDA, double precision, dimension( * )AP, integerINFO)

**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.

**Date:**

September 2012

Definition at line 105 of file dtrttp.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

dtrttp(3) is an alias of dtrttp.f(3).