DPPDI(3F)DPPDI(3F)NAMEDPPDI - DPPDI computes the determinant and inverse of a double
precision symmetric positive definite matrix using the factors computed
by DPPCO or DPPFA .
SYNOPSYS
SUBROUTINE DPPDI(AP,N,DET,JOB)
DESCRIPTION
On Entry
AP DOUBLE PRECISION (N*(N+1)/2)
the output from DPPCO or DPPFA.
N INTEGER
the order of the matrix A .
JOB INTEGER
= 11 both determinant and inverse.
= 01 inverse only.
= 10 determinant only. On Return
AP the upper triangular half of the inverse .
The strict lower triangle is unaltered.
DET DOUBLE PRECISION(2)
determinant of original matrix if requested.
Otherwise not referenced.
DETERMINANT = DET(1) * 10.0**DET(2)
with 1.0 .LE. 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 DPOCO or DPOFA has set INFO .EQ.
0 . LINPACK. This version dated 08/14/78 . Cleve Moler, University of
New Mexico, Argonne National Lab. Subroutines and Functions BLAS
DAXPY,DSCAL Fortran MOD
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