 LAPACK  3.4.2 LAPACK: Linear Algebra PACKage
dtpttr.f File Reference

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## Functions/Subroutines

subroutine dtpttr (UPLO, N, AP, A, LDA, INFO)
DTPTTR copies a triangular matrix from the standard packed format (TP) to the standard full format (TR).

## Function/Subroutine Documentation

 subroutine dtpttr ( character UPLO, integer N, double precision, dimension( * ) AP, double precision, dimension( lda, * ) A, integer LDA, integer INFO )

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

``` DTPTTR copies a triangular matrix A from standard packed format (TP)
 [in] UPLO ``` UPLO is CHARACTER*1 = 'U': A is upper triangular. = 'L': A is lower triangular.``` [in] N ``` N is INTEGER The order of the matrix A. N >= 0.``` [in] AP ``` AP is DOUBLE PRECISION array, dimension ( N*(N+1)/2 ), 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.``` [out] 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.``` [in] LDA ``` LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N).``` [out] INFO ``` INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value```