> I have a problem with calculating a fraction, the reason is that both > the nominator and denominator are variables. > So I am looking for some way to make this linear: > x_suj = p_s * (y_suj/w_su) or well just find what this fraction > is: y_suj/w_su > where p_s is a constant, x,y and w are integer variables. and I also > need to avoid the division with 0 problem. > Anyone know some tips/tricks for this?
Another way is to replace the variables by their logarithms: ln x_suj = ln p_s + ln y_suj - ln w_su and then, depending on the context, model the exponenta z = exp(ln z) by a piecewise linear function using SOS2 constraints; see http://lists.gnu.org/archive/html/help-glpk/2007-06/msg00005.html http://winglpk.sourceforge.net/media/glpk-sos2_02.pdf _______________________________________________ Help-glpk mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-glpk
