Re: [Help-glpk] Status of basic solution

[Andrew Makhorin]

> I'm writing a procedure where I make some modifications to the basis of
> a simplex tableau by pivoting pairs of variables (using the 
> lpx_set_[col|row]_stat and lpx_warm_up functions). I then check the 
> status of the basic solution I obtain using lpx_get_status.
> One of the status that can be reported by GLPK is: LPX_UNDEF, "solution 
> is undefined". Does anyone know what this means for GLPK, please ?

LPX_UNDEF means that primal and dual solution components have been not
computed yet or some components of lp instance have been changed since
the last call to lpx_simplex or lpx_warm_up. Most probably lpx_warm_up
failed; check its return code.