dpptri
dpptri - compute the inverse of a real symmetric positive definite matrix A using the Cholesky factorization A = U**T*U or A = L*L**T computed by SPPTRF
SUBROUTINE DPPTRI( UPLO, N, A, INFO)
CHARACTER * 1 UPLO
INTEGER N, INFO
DOUBLE PRECISION A(*)
SUBROUTINE DPPTRI_64( UPLO, N, A, INFO)
CHARACTER * 1 UPLO
INTEGER*8 N, INFO
DOUBLE PRECISION A(*)
SUBROUTINE PPTRI( UPLO, N, A, [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER :: N, INFO
REAL(8), DIMENSION(:) :: A
SUBROUTINE PPTRI_64( UPLO, N, A, [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, INFO
REAL(8), DIMENSION(:) :: A
#include <sunperf.h>
void dpptri(char uplo, int n, double *a, int *info);
void dpptri_64(char uplo, long n, double *a, long *info);
dpptri computes the inverse of a real symmetric positive definite
matrix A using the Cholesky factorization A = U**T*U or A = L*L**T
computed by SPPTRF.
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* UPLO (input)
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* N (input)
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The order of the matrix A. N >= 0.
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* A (input/output)
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On entry, the triangular factor U or L from the Cholesky
factorization A = U**T*U or A = L*L**T, packed columnwise as
a linear array. The j-th column of U or L is stored in the
array A as follows:
if UPLO = 'U', A(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = 'L', A(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.
On exit, the upper or lower triangle of the (symmetric)
inverse of A, overwriting the input factor U or L.
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* INFO (output)
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