Matrix inverse

The inverse of a scalar matrix may be used by using the `Inverse`
function of the `BIAS/Profil` package or with

void ALIAS_MRINVD(VECTOR &A,VECTOR &B,int N,int *KOD,double *DET,double EPS, INTEGER_VECTOR &IL,INTEGER_VECTOR &IC)where

`A`is the matrix given by column`B`is the inverse of`A``N`is the dimension of the matrix`KOD`is a return code. If`KOD`is 0 then`A`is estimated not to have an inverse, otherwise`KOD`is set to 1`DET`: the determinant of`A``EPS`: a threshold, if a pivot has an abolute value less than this value, then it is assumed to be 0`IL, IC`: working table of size`N`

The inverse of an interval matrix may be defined as the set of matrices corresponding to the inverse of a matrix included in the set defined by the interval matrix. This set cannot usually be computed exactly but a set of matrices guaranteed to include the inverse interval matrix may be computed. The following procedure allows one to compute such overestimation.

int Inverse_Interval_Matrix(int Dim,int cond,INTERVAL_MATRIX &Jac,INTERVAL_MATRIX &InvJac)

where `Dim` is the dimension of the matrix `Jac`. The flag
`cond` has to be set to 1 if pre-conditioning is used, 0
otherwise. Pre-conditionning will usually leads to a smaller
overestimation but is more computer intensive.
This procedures returns 1 if it has been able to compute the inverse,
0 otherwise.

Note that using this procedure should not be used for solving an interval linear system.