SSISL(3F)
SSISL - SSISL solves the real symmetric system A * X = B using the factors computed by SSIFA.
As shipped in IRIX 6.5.30. Unchanged since IRIX 6.5.
NAME SSISL - SSISL solves the real symmetric system A * X = B using the factors computed by SSIFA. SYNOPSYS SUBROUTINE SSISL(A,LDA,N,KPVT,B) DESCRIPTION On Entry A REAL(LDA,N) the output from SSIFA. LDA INTEGER the leading dimension of the array A . N INTEGER the order of the matrix A . KPVT INTEGER(N) the pivot vector from SSIFA. B REAL(N) the right hand side vector. On Return B the solution vector X . Error Condition A division by zero may occur if SSICO has set RCOND .EQ. 0.0 or SSIFA has set INFO .NE. 0 . To compute INVERSE(A) * C where C is a matrix with P columns CALL SSIFA(A,LDA,N,KPVT,INFO) IF (INFO .NE. 0) GO TO ... DO 10 J = 1, P CALL SSISL(A,LDA,N,KPVT,C(1,J)) 10 CONTINUE LINPACK. This version dated 08/14/78 . James Bunch, Univ. Calif. San Diego, Argonne Nat. Lab. Subroutines and Functions BLAS SAXPY,SDOT Fortran IABS