Hi,
I agree with Roberto that all of the symptoms suggest that Apple gcc-4.2 is miscompiling something (and we would really appreciate if someone can try out using a newer gcc).
The first differences above are related to a very simple MIP problem test. Can you please provide us with the output of the following command:
$ cd <PATH_TO_PPL_BUILD>/demos/ppl_lpsol $ ./ppl_lpsol -s -p1 -v 4 -c -M <PATH_TO_PPL_SRC>/demos/ppl_lpsol/examples/ex1.mps
This will also show the problem as read from the input, which should be something like: ============= Integer variables: x1 x2 Constraints: -2*x1 - x2 >= -5 4*x1 - 4*x2 >= -5 x1 >= 0 x2 >= 0 Objective function: x1 - 2*x2 Maximizing. =============
Hi, On 10.6/i686, apple-gcc-4.2, gmp-5.0.1, I get:
fang@fangbook 4> ./ppl_lpsol -s -p1 -v 4 -c -M ../../../demos/ppl_lpsol/examples/ex1.mps Integer variables: x1 x2 Constraints: -2*x1 - x2 >= -5 4*x1 - 4*x2 >= -5 x1 >= 0 -x1 >= -1 x2 >= 0 -x2 >= -1 Objective function: x1 - 2*x2 Maximizing. Optimum value: 1 Optimum location: x1 = 1 x2 = 0
Different indeed! Does this indicate an earlier parse error?
Fang
Well ... ppl_lpsol uses glpk to parse the input file. Apparently, the installed glpk is parsing the input file differently. Which version of glpk do you have?
If I am to guess, I would say that the installed glpk is flagging the two variables as being *binary* variables, rather than *integer* ones. But this is just a guess, I will have to check the documentation for the input file format as well as the changelog for glpk.
I have glpk-4.44:
fang@fangbook 6> fink list -t glpk Information about 10198 packages read in 9 seconds. i glpk 4.44-1 GNU Linear Programming Kit i glpk-dev 4.44-1 GNU Linear Programming Kit glpk-java 4.19-1 Java bindings for GLPK i glpk-shlibs 4.44-1 GNU Linear Programming Kit
Apart from this, ppl_lpsol seems to be correctly doing its job in optimizing the problem (and use of option -c seems to confirm that glpk is computing the very same optimal value).
Enea.
That's good to know that ppl is doing its part of the work 'correctly'. Anything else I can test for you?
Fang
David Fang http://www.csl.cornell.edu/~fang/ http://www.achronix.com/