Initializing help system before first use

# getiis

Purpose
Compute then get the Irreductible Infeasible Sets (IIS).
Synopsis
`procedure getiis(vset:set of mpvar,cset:set of linctr)`
`procedure getiis(vset:set of mpvar,cset:set of linctr,nset:set of nlctr,lset:set of logctr)`
`procedure getiis(numiis:integer,vset:set of mpvar,cset:set of linctr)`
`procedure getiis(numiis:integer,vset:set of mpvar,cset:set of linctr,nset:set of nlctr,lset:set of logctr)`
`procedure getiis(numiis:integer,ctype:array(linctr) of integer)`
`procedure getiis(numiis:integer,ctype:array(linctr) of integer,ntype:array(nlctr) of integer,ltype:array(logctr) of integer)`
`procedure getiis(numiis:integer,duals:array(linctr) of real)`
`procedure getiis(numiis:integer,isolrow:array(linctr) of boolean)`
`procedure getiis(numiis:integer,bndtype:array(mpvar) of integer)`
`procedure getiis(numiis:integer,rdcs:array(mpvar) of real)`
`procedure getiis(numiis:integer,isolcol:array(mpvar) of boolean)`
Arguments

vset | Set to return the decision variables of the IIS or {} if not required
cset | Set to return the linear constraints and sets of the IIS or {} if not required
nset | Set to return the nonlinear constraints of the IIS or {} if not required
lset | Set to return the indicator constraints of the IIS or {} if not required
numiis | Ordinal number of the IIS
ctype | Array to return the sense or type of linear rows and sets in the IIS ( XPRS_IIS_LEQ, XPRS_IIS_GEQ, XPRS_IIS_EQ , XPRS_IIS_SOS1, XPRS_IIS_SOS2)
ntype | Array to return the sense or type of nonlinear rows in the IIS ( XPRS_IIS_LEQ, XPRS_IIS_GEQ, XPRS_IIS_EQ)
ltype | Array to return the indicator rows in the IIS ( XPRS_IIS_INDIC is returned for every indicator row)
duals | Array to return the dual multipliers associated with the linear rows of the IIS
isolrow | Array to return the isolation status of the the linear rows of the IIS
bndtype | Array to return the encoded sense and type of bounds in the IIS
rdcs | Array to return the dual multipliers associated with the bounds of the IIS
isolcol | Array to return the isolation status of the the bounds of the IIS

Further information
1. This procedure computes the IIS and stores the result in the provided parameters. The first two forms of the routine ( numiis not specified) compute all IIS and return the last set found. For LPs, multiple IIS may be found, and the number of IIS available can be determined using the XPRS_numiis parameter. For other problem types, only a single IIS will be identified.
2. For LPs, numiis specifies which IIS to return, numbered from 1. If numiis is 0, an initial approximation of an IIS is computed, consisting of rows and columns with a nonzero Lagrange multiplier.
3. The bndtype values have to be decoded using getiissense and getiistype. The first routine may return XPRS_IIS_LEQ (upper bound), XPRS_IIS_GEQ (lower bound), XPRS_IIS_RNG (lower and upper bound) or XPRS_IIS_EQ (fixed bound). The second one may give XPRS_IIS_BIN (binary), XPRS_IIS_INT (integer), XPRS_IIS_PINT (partial integer), XPRS_IIS_SEC (semi continuous) or XPRS_IIS_SINT (semi continuous integer).
4. The IIS procedure does not support models containing logical constraints. The only logctrs permitted in the model are those representing indicator constraints.
5. The sets passed to this procedure are reset before being used.
Related topics
resetiis, isiisvalid, getinfeas.
Module
mmxprs
Parent Topic Procedures and functions

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