Sample file completed: works correctly and the code is very beautiful. I love LEMON.
1.1 --- a/src/work/athos/lp/lp_sample.cc Thu Apr 07 11:30:12 2005 +0000
1.2 +++ b/src/work/athos/lp/lp_sample.cc Thu Apr 07 12:54:35 2005 +0000
1.3 @@ -1,15 +1,48 @@
1.4 -//#include <stdio.h>
1.5 -//#include <stdlib.h>
1.6 #include <iostream>
1.7 #include <lemon/lp_glpk.h>
1.8 using namespace lemon;
1.9
1.10 int main()
1.11 {
1.12 + //The following example is taken from the documentation of the GLPK library.
1.13 + //See it in the GLPK reference manual and among the GLPK sample files (sample.c)
1.14 LpGlpk lp;
1.15 typedef LpGlpk::Row Row;
1.16 typedef LpGlpk::Col Col;
1.17 - //std::cout << "Hello" << std::endl;
1.18 +
1.19 + lp.max();
1.20 +
1.21 + Col x1 = lp.addCol();
1.22 + Col x2 = lp.addCol();
1.23 + Col x3 = lp.addCol();
1.24 +
1.25 + //One solution
1.26 + // Row p = lp.addRow();
1.27 + // Row q = lp.addRow();
1.28 + // Row r = lp.addRow();
1.29 + // lp.setRow(p,x1+x2+x3 <=100);
1.30 + // lp.setRow(q,10*x1+4*x2+5*x3<=600);
1.31 + // lp.setRow(r,2*x1+2*x2+6*x3<=300);
1.32 +
1.33 + //A more elegant one
1.34 + //Constraints
1.35 + lp.addRow(x1+x2+x3 <=100);
1.36 + lp.addRow(10*x1+4*x2+5*x3<=600);
1.37 + lp.addRow(2*x1+2*x2+6*x3<=300);
1.38 + //Nonnegativity of the variables
1.39 + lp.colLowerBound(x1, 0);
1.40 + lp.colLowerBound(x2, 0);
1.41 + lp.colLowerBound(x3, 0);
1.42 + //Objective function
1.43 + lp.setObj(10*x1+6*x2+4*x3);
1.44 +
1.45 + lp.solve();
1.46 +
1.47 + printf("\nZ = %g; x1 = %g; x2 = %g; x3 = %g\n",
1.48 + lp.primalValue(),
1.49 + lp.primal(x1), lp.primal(x2), lp.primal(x3));
1.50 +
1.51 + //Here comes the same problem written in C using GLPK API routines
1.52
1.53 // LPX *lp;
1.54 // int ia[1+1000], ja[1+1000];
1.55 @@ -17,29 +50,16 @@
1.56 // s1: lp = lpx_create_prob();
1.57 // s2: lpx_set_prob_name(lp, "sample");
1.58 // s3: lpx_set_obj_dir(lp, LPX_MAX);
1.59 - lp.max();
1.60 // s4: lpx_add_rows(lp, 3);
1.61 // s5: lpx_set_row_name(lp, 1, "p");
1.62 // s6: lpx_set_row_bnds(lp, 1, LPX_UP, 0.0, 100.0);
1.63 -
1.64 -// Row p = lp.addRow();
1.65 -
1.66 // s7: lpx_set_row_name(lp, 2, "q");
1.67 // s8: lpx_set_row_bnds(lp, 2, LPX_UP, 0.0, 600.0);
1.68 -
1.69 -// Row q = lp.addRow();
1.70 -
1.71 // s9: lpx_set_row_name(lp, 3, "r");
1.72 // s10: lpx_set_row_bnds(lp, 3, LPX_UP, 0.0, 300.0);
1.73 -
1.74 -// Row r = lp.addRow();
1.75 -
1.76 // s11: lpx_add_cols(lp, 3);
1.77 // s12: lpx_set_col_name(lp, 1, "x1");
1.78 // s13: lpx_set_col_bnds(lp, 1, LPX_LO, 0.0, 0.0);
1.79 -
1.80 -// Col x1 = lp.addCol();
1.81 -
1.82 // s14: lpx_set_obj_coef(lp, 1, 10.0);
1.83 // s15: lpx_set_col_name(lp, 2, "x2");
1.84 // s16: lpx_set_col_bnds(lp, 2, LPX_LO, 0.0, 0.0);
1.85 @@ -65,5 +85,6 @@
1.86 // s36: printf("\nZ = %g; x1 = %g; x2 = %g; x3 = %g\n", Z, x1, x2, x3);
1.87 // s37: lpx_delete_prob(lp);
1.88 // return 0;
1.89 +
1.90 return 0;
1.91 }