[Help-glpk] lx_set_col_bnds() - a bit strange

[Michael Jastrzebski]

I found a strange thing.

I had two lines of code that set both lower and upper bounds on the column:

lpx_set_col_bnds(lp,col,LPX_LO,0.0,0.0); /* set lower to zero */
lpx_set_col_bnds(lp,col,LPX_UP,1.0,1.0); /* set upper to 1 */

and this did not do the job - I got solutions that were negative.

But when I reversed order:

lpx_set_col_bnds(lp,col,LPX_UP,1.0,1.0);
lpx_set_col_bnds(lp,col,LPX_LO,0.0,0.0);

Everything seems ok.

Michael J.