zgbfa
zgbfa - (obsolete) compute the LU factorization of a matrix A in banded storage. It is typical to follow a call to CGBFA with a call to CGBSL to solve Ax = b or to CGBDI to compute the determinant of A.
SUBROUTINE ZGBFA( A, LDA, N, NSUB, NSUPER, IPIVOT, INFO)
DOUBLE COMPLEX A(LDA,*)
INTEGER LDA, N, NSUB, NSUPER, INFO
INTEGER IPIVOT(*)
SUBROUTINE ZGBFA_64( A, LDA, N, NSUB, NSUPER, IPIVOT, INFO)
DOUBLE COMPLEX A(LDA,*)
INTEGER*8 LDA, N, NSUB, NSUPER, INFO
INTEGER*8 IPIVOT(*)
#include <sunperf.h>
void zgbfa(doublecomplex *a, int lda, int n, int nsub, int nsuper, int *ipivot, int *info);
void zgbfa_64(doublecomplex *a, long lda, long n, long nsub, long nsuper, long *ipivot, long *info);
-
* A (input/output)
-
On entry, the matrix A. On exit, an LU factorization of the matrix A.
-
* LDA (input)
-
Leading dimension of the array A as specified in a dimension or type statement. LDA >= 2 * NSUB + NSUPER + 1.
-
* N (input)
-
Order of the matrix A. N >= 0.
-
* NSUB (input)
-
Number of subdiagonals of A. N-1 >= NSUB >= 0 but if N = 0 then NSUB = 0.
-
* NSUPER (input)
-
Number of superdiagonals of A. N-1 >= NSUPER >= 0 but if N = 0 then NSUPER = 0.
-
* IPIVOT (output)
-
On exit, a vector of pivot indices.
-
* INFO (output)
-
On exit:
INFO = 0 Subroutine completed normally.
INFO > 0 Returns a value k if U(k,k) = 0 to indicate that CGBSL will divide by zero if called.