---
name: "strttp"
section: "3lapack"
platform: "linux"
package: "liblapack-doc"
version: "3.2.1-8"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/strttp/3lapack"
---

# strttp(3lapack)

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

## NAME

STRTTP - copies a triangular matrix A from full format (TR) to standard packed format (TP)

## SYNOPSIS

- SUBROUTINE STRTTP(

  UPLO, N, A, LDA, AP, INFO )

- CHARACTER

  UPLO

- INTEGER

  INFO, N, LDA

- REAL

  A( LDA, \* ), AP( \* )

## PURPOSE

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

## ARGUMENTS

- UPLO (input) CHARACTER

  \= 'U':  A is upper triangular.\
   \= 'L':  A is lower triangular.

- N (input) INTEGER

  The order of the matrices AP and A.  N \>= 0.

- A (input) REAL 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 (input) INTEGER

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

- AP (output) REAL 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 (output) INTEGER

  \= 0:  successful exit\
   \< 0:  if INFO = -i, the i-th argument had an illegal value