DSPSL(3F)DSPSL(3F)NAMEDSPSL - DSISL solves the double precision symmetric system A * X = B
using the factors computed by DSPFA.
SYNOPSYS
SUBROUTINE DSPSL(AP,N,KPVT,B)
DESCRIPTION
On Entry
AP DOUBLE PRECISION(N*(N+1)/2)
the output from DSPFA.
N INTEGER
the order of the matrix A .
KPVT INTEGER(N)
the pivot vector from DSPFA.
B DOUBLE PRECISION(N)
the right hand side vector. On Return
B the solution vector X . Error Condition
A division by zero may occur if DSPCO has set RCOND .EQ. 0.0 or DSPFA
has set INFO .NE. 0 . To compute INVERSE(A) * C where C is a matrix
with P columns
CALL DSPFA(AP,N,KPVT,INFO)
IF (INFO .NE. 0) GO TO ...
DO 10 J = 1, P
CALL DSPSL(AP,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 DAXPY,DDOT Fortran IABS
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