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cmex problem (lp_solve) with solaris 2.5
Posted:
Jul 16, 1996 8:43 PM


Hi,
I'm with Dr. Kantor's group at Notre Dame (process control) and we had written a cmex file (for SunOS4.1.3) for a popular linear program solver, lp_solve, which was made available publically.
We are now trying to make it work for MATLAB4.2c under solaris 2.5.
The C code compiles and runs fine by itself in solaris, the .mexsol cmex file is also compiled without any problems, and it even works ok for all of its segments, except one part. i.e. we can input and output parameters to and from the C file to MATLAB, make a lp, scale it, add constraints etc., but when we try to solve it, we get a MATLAB bus error.
I would appreciate it if someone could provide some suggestions, when bus errors occur, or if someone has had similar experiences with MATLAb under solaris 2.5 (since the mathworks does not yet support matlab 4.2c under this solaris version)
thanks very much,
saurabh

Here's an example of the above problem :
>> f = [1 2]'; >> A = [2 1;4 4]; >> b = [5 5]; >> e = [1 1]; >> xint = [1 2];
this is the LP input part, it works fine :
>> [m,n] = size(a); >> lp = lpmex('make_lp',m,n); >> lpmex('set_mat', lp, a); >> lpmex('set_rh_vec', lp, b); >> lpmex('set_obj_fn', lp, f); >> lpmex('set_maxim', lp); % default is solving minimum lp. >> >> for i = 1:length(e) lpmex('set_constr_type', lp, i,e(i)+1); end >> >> for i = 1:length(xint) lpmex('set_int', lp,xint(i),1); end
We can also output the LP back into MATLAB :
>> lpmex('print_handle')
ans =
0 1
>> lpmex('print_lp',0) problem name: unnamed Var[ 1] Var[ 2] Maximise 1.00 2.00 Row[ 1] 2.00 1.00 <= 5.00 Row[ 2] 4.00 4.00 <= 5.00 Type Int Int upbo Inf Inf lowbo 0.00 0.00
But when we try to solve :
>> lpmex('solve',0)
 MATLAB bus error detected !!! 
Please report this problem to The MathWorks if you can replicate it. We need as much information as you can provide! Please include at least the following:
1. MATLAB version number 2. Platform type, Operating System and Window System versions 3. Sample commands, Mfiles, or MEXfiles that reproduce the error 4. Any other pertinent configuration information
Either Email the information to:
support@mathworks.com
or FAX this information to:
5086532997.
Try to save your workspace and quit. Error in ==> /afs/nd.edu/user13/sthapliy/LP_SOLVE/lpmex.mexsol



