Re: [Help-glpk] glpk 4.42 release information

[Yingjie Lan]

> GLPK 4.42 -- Release Information
> ********************************
> 
> Release date: Jan 13, 2010
> 
> GLPK (GNU Linear Programming Kit) is intended for solving
> large-scale
> linear programming (LP), mixed integer linear programming
> (MIP), and
> other related problems. It is a set of routines written in
> ANSI C and
> organized as a callable library.
> 
> In this release:
> 
>         The following new API routines
> were added:
> 
>         glp_check_dup   
>      check for duplicate elements in
> sparse
>                
>               matrix
>         glp_sort_matrix   
>    sort elements of the constraint matrix
>         glp_read_prob   
>      read problem data in GLPK format
>         glp_write_prob   
>     write problem data in GLPK format
>         glp_analyze_bound 
>    analyze active bound of non-basic
> variable
>         glp_analyze_coef   
>   analyze objective coefficient at basic
>                
>               variable
>         glp_print_ranges   
>   print sensitivity analysis report (this
>                
>               routine
> replaces lpx_print_sens_bnds and
>                
>               makes it
> deprecated)

Thanks, quickly looked at the reference manual and it looks really good. The 
sensitivity report preamble message has been turned off, which is nice. But I'm 
not sure what would happen if you give glp_analyze_coef a none-basic variable? 
Similarly, what would happen if you give glp_analyze_bound a basic variable? 
The reference manual does not mention this, it seems to me. BTW, I'm not sure 
how to check if a variable is basic or not, simply checking if the value is at 
one of its bounds is easy but not a reliable way to do this.

I am very excited about this new release, maybe I will directly incorporate 
GLPK into PyMathProg, so that you don't need to install GLPK separately, nor 
worry about which version compatibility issues.

Regards,

Yingjie