dpbfa
dpbfa - (obsolete) compute a Cholesky factorization of a symmetric positive definite matrix
A in banded storage. It is typical to follow a call to SPBFA with a call to SPBSL to solve Ax = b or to SPBDI to
compute the determinant of A.
SUBROUTINE DPBFA( A, LDA, N, NDIAG, INFO)
INTEGER LDA, N, NDIAG, INFO
DOUBLE PRECISION A(LDA,*)
SUBROUTINE DPBFA_64( A, LDA, N, NDIAG, INFO)
INTEGER*8 LDA, N, NDIAG, INFO
DOUBLE PRECISION A(LDA,*)
#include <sunperf.h>
void dpbfa(double *a, int lda, int n, int ndiag, int *info);
void dpbfa_64(double *a, long lda, long n, long ndiag, long *info);
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* A (input/output)
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On entry, the upper triangle of the matrix A.
On exit, a Cholesky factorization of the matrix A.
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* LDA (input)
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Leading dimension of the array A as specified in a dimension or
type statement. LDA >= NDIAG + 1.
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* N (input)
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Order of the matrix A. N >= 0.
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* NDIAG (input)
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Number of diagonals. N-1 >= NDIAG >= 0 but if N = 0 then NDIAG = 0.
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* INFO (output)
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On exit:
INFO = 0 Subroutine completed normally.
INFO > 0 Returns a value of k if the leading minor of order k
is not positive definite.