CGEDI(3)

SYNOPSIS
SUBROUTINE CGEDI (A, LDA, N, IPVT, DET, WORK, JOB)

NAME
cgedi - Compute the determinant and inverse of a matrix using the factors computed by CGECO or CGEFA.

LIBRARY
SLATEC (LINPACK)

CATEGORY
D2C1, D3C1

TYPE
COMPLEX (SGEDI-S, DGEDI-D, CGEDI-C)

KEYWORDS
DETERMINANT, INVERSE, LINEAR ALGEBRA, LINPACK, MATRIX

AUTHOR
Moler, C. B., (U. of New Mexico)

DESCRIPTION
CGEDI computes the determinant and inverse of a matrix using the factors computed by CGECO or CGEFA. On Entry A COMPLEX(LDA, N) the output from CGECO or CGEFA. LDA INTEGER the leading dimension of the array A . N INTEGER the order of the matrix A . IPVT INTEGER(N) the pivot vector from CGECO or CGEFA. WORK COMPLEX(N) work vector. Contents destroyed. JOB INTEGER = 11 both determinant and inverse. = 01 inverse only. = 10 determinant only. On Return A inverse of original matrix if requested. Otherwise unchanged. DET COMPLEX(2) determinant of original matrix if requested. Otherwise not referenced. Determinant = DET(1) * 10.0**DET(2) with 1.0 .LE. CABS1(DET(1)) .LT. 10.0 or DET(1) .EQ. 0.0 . Error Condition A division by zero will occur if the input factor contains a zero on the diagonal and the inverse is requested. It will not occur if the subroutines are called correctly and if CGECO has set RCOND .GT. 0.0 or CGEFA has set INFO .EQ. 0 .

REFERENCES
J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W. Stewart, LINPACK Users' Guide, SIAM, 1979.

ROUTINES CALLED
CAXPY, CSCAL, CSWAP

REVISION HISTORY (YYMMDD)
780814 DATE WRITTEN
890831 Modified array declarations. (WRB)
890831 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900326 Removed duplicate information from DESCRIPTION section. (WRB)
920501 Reformatted the REFERENCES section. (WRB)