Provided by: liblapack-doc_3.3.1-1_all

**NAME**

LAPACK-3 - copies a triangular matrix A from full format (TR) to standard packed format (TP)

**SYNOPSIS**

SUBROUTINE DTRTTP( UPLO, N, A, LDA, AP, INFO ) CHARACTER UPLO INTEGER INFO, N, LDA DOUBLE PRECISION A( LDA, * ), AP( * )

**PURPOSE**

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

**ARGUMENTS**

UPLO (input) CHARACTER*1 = '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) 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 (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). AP (output) 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 (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value LAPACK routine (version 3.3.0) April 2011 DTRTTP(3lapack)