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comparison R/rdyncall/demo/glpk.R @ 0:0cfcc391201f

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initial from svn dyncall-1745
author Daniel Adler
date Thu, 19 Mar 2015 22:26:28 +0100
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-1:000000000000 0:0cfcc391201f
1 # Example from GLPK Reference Manual.. rewritten to R.
2
3 dynport(glpk)
4 lp = glp_create_prob();
5 glp_set_prob_name(lp, "sample");
6 glp_set_obj_dir(lp, GLP_MAX);
7 glp_add_rows(lp, 3);
8 glp_set_row_name(lp, 1, "p");
9 glp_set_row_bnds(lp, 1, GLP_UP, 0.0, 100.0);
10 glp_set_row_name(lp, 2, "q");
11 glp_set_row_bnds(lp, 2, GLP_UP, 0.0, 600.0);
12 glp_set_row_name(lp, 3, "r");
13 glp_set_row_bnds(lp, 3, GLP_UP, 0.0, 300.0);
14 glp_add_cols(lp, 3);
15 glp_set_col_name(lp, 1, "x1");
16 glp_set_col_bnds(lp, 1, GLP_LO, 0.0, 0.0);
17 glp_set_obj_coef(lp, 1, 10.0);
18 glp_set_col_name(lp, 2, "x2");
19 glp_set_col_bnds(lp, 2, GLP_LO, 0.0, 0.0);
20 glp_set_obj_coef(lp, 2, 6.0);
21 glp_set_col_name(lp, 3, "x3");
22 glp_set_col_bnds(lp, 3, GLP_LO, 0.0, 0.0);
23 glp_set_obj_coef(lp, 3, 4.0);
24
25 ia = integer(1+1000)
26 ja = integer(1+1000)
27 ar = double(1+1000)
28
29 #we index at 1 in C (second position).. but in R we start at initial position..
30 ia[1]=1;ja[1]=1;ar[1]= 1.0;
31 ia[2]=1;ja[2]=2;ar[2]= 1.0;
32 ia[3]=1;ja[3]=3;ar[3]= 1.0;
33 ia[4]=2;ja[4]=1;ar[4]= 10.0;
34 ia[5]=3;ja[5]=1;ar[5]= 2.0;
35 ia[6]=2;ja[6]=2;ar[6]= 4.0;
36 ia[7]=3;ja[7]=2;ar[7]= 2.0;
37 ia[8]=2;ja[8]=3;ar[8]= 5.0;
38 ia[9]=3;ja[9]=3;ar[9]= 6.0;
39
40 #now we prefix with '0' .. so that our values the above start at 1 in C.
41
42 ia <- as.integer(c(0,ia))
43 ja <- as.integer(c(0,ja))
44
45 glp_load_matrix(lp, 9, ia, ja, ar);
46 glp_simplex(lp, NULL);
47 z = glp_get_obj_val(lp);
48 x1 = glp_get_col_prim(lp, 1);
49 x2 = glp_get_col_prim(lp, 2);
50 x3 = glp_get_col_prim(lp, 3);
51
52 print(list(z=z,x1=x1,x2=x2,x3=x3))
53 glp_delete_prob(lp);