CGESL(3F)
CGESL - CGESL solves the complex system A * X = B or CTRANS(A) * X = B using the factors computed by CGECO or CGEFA.
As shipped in IRIX 6.5.22. Unchanged since IRIX 6.5.
NAME CGESL - CGESL solves the complex system A * X = B or CTRANS(A) * X = B using the factors computed by CGECO or CGEFA. SYNOPSYS SUBROUTINE CGESL(A,LDA,N,IPVT,B,JOB) DESCRIPTION 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. B COMPLEX(N) the right hand side vector. JOB INTEGER = 0 to solve A*X = B , = nonzero to solve CTRANS(A)*X = B where CTRANS(A) is the conjugate transpose. On Return B the solution vector X . Error Condition A division by zero will occur if the input factor contains a zero on the diagonal. Technically this indicates singularity but it is often caused by improper arguments or improper setting of LDA . 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 . To compute INVERSE(A) * C where C is a matrix with P columns CALL CGECO(A,LDA,N,IPVT,RCOND,Z) IF (RCOND is too small) GO TO ... DO 10 J = 1, P CALL CGESL(A,LDA,N,IPVT,C(1,J),0) 10 CONTINUE LINPACK. This version dated 08/14/78 . Cleve Moler, University of New Mexico, Argonne National Lab. Subroutines and Functions BLAS CAXPY,CDOTC Fortran CONJG