cgesl.f
SUBROUTINE CGESL (A, LDA, N, IPVT, B, JOB)
C***BEGIN PROLOGUE CGESL
C***PURPOSE Solve the complex system A*X=B or CTRANS(A)*X=B using the
C factors computed by CGECO or CGEFA.
C***LIBRARY SLATEC (LINPACK)
C***CATEGORY D2C1
C***TYPE COMPLEX (SGESL-S, DGESL-D, CGESL-C)
C***KEYWORDS LINEAR ALGEBRA, LINPACK, MATRIX, SOLVE
C***AUTHOR Moler, C. B., (U. of New Mexico)
C***DESCRIPTION
C
C CGESL solves the complex system
C A * X = B or CTRANS(A) * X = B
C using the factors computed by CGECO or CGEFA.
C
C On Entry
C
C A COMPLEX(LDA, N)
C the output from CGECO or CGEFA.
C
C LDA INTEGER
C the leading dimension of the array A .
C
C N INTEGER
C the order of the matrix A .
C
C IPVT INTEGER(N)
C the pivot vector from CGECO or CGEFA.
C
C B COMPLEX(N)
C the right hand side vector.
C
C JOB INTEGER
C = 0 to solve A*X = B ,
C = nonzero to solve CTRANS(A)*X = B where
C CTRANS(A) is the conjugate transpose.
C
C On Return
C
C B the solution vector X .
C
C Error Condition
C
C A division by zero will occur if the input factor contains a
C zero on the diagonal. Technically this indicates singularity
C but it is often caused by improper arguments or improper
C setting of LDA . It will not occur if the subroutines are
C called correctly and if CGECO has set RCOND .GT. 0.0
C or CGEFA has set INFO .EQ. 0 .
C
C To compute INVERSE(A) * C where C is a matrix
C with P columns
C CALL CGECO(A,LDA,N,IPVT,RCOND,Z)
C IF (RCOND is too small) GO TO ...
C DO 10 J = 1, P
C CALL CGESL(A,LDA,N,IPVT,C(1,J),0)
C 10 CONTINUE
C
C***REFERENCES J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
C Stewart, LINPACK Users' Guide, SIAM, 1979.
C***ROUTINES CALLED CAXPY, CDOTC
C***REVISION HISTORY (YYMMDD)
C 780814 DATE WRITTEN
C 890831 Modified array declarations. (WRB)
C 890831 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900326 Removed duplicate information from DESCRIPTION section.
C (WRB)
C 920501 Reformatted the REFERENCES section. (WRB)
C***END PROLOGUE CGESL