Hi, all! I need to solve a problem in witch some statements may restricts a variable above a small value, e.g. 1e-4. But after solving, GLPSOL is setting this variable equals to zero.
If I run this problem using "--exact" argument, it works as expected, but
it uses much more memory. Is there any argument or work arround to o run
this problem in glpsol without using exact arithimetic?
*Example:*
In the simple example attached, the minimun value for "x" must be
"delta_min", but in my tests:
if delta_min < 1e-3, x results in 0 (even for delta_min = 9.999e-4)
*(1) - Using "statement_test_0.0001.dat" file, the result is wrong:*
3 rows, 1 column, 3 non-zeros
Preprocessing...
~ 0: obj = 0.000000000e+000 infeas = 0.000e+000
OPTIMAL SOLUTION FOUND BY LP PREPROCESSOR
Time used: 0.0 secs
Memory used: 0.1 Mb (88615 bytes)
Display statement at line 14
x.val = 0
x = 0.0000000000000000
Display statement at line 17
delta_min = 0.0001
Display statement at line 18
delta_max = 0.0002
Model has been successfully processed
*(2) - Using "statement_test_0.001.dat" file, the result is correct:*
3 rows, 1 column, 3 non-zeros
Preprocessing...
~ 0: obj = 1.000000000e-003 infeas = 0.000e+000
OPTIMAL SOLUTION FOUND BY LP PREPROCESSOR
Time used: 0.0 secs
Memory used: 0.1 Mb (88615 bytes)
Display statement at line 14
x.val = 0.001
x = 0.0010000000000000
Display statement at line 17
delta_min = 0.001
Display statement at line 18
delta_max = 0.002
Model has been successfully processed
*(3) - Running (1) with "--exact" argument, the result is correct, but uses
more memory:*
glp_exact: 3 rows, 1 columns, 3 non-zeros
GLPK bignum module is being used
(Consider installing GNU MP to attain a much better performance.)
0: infsum = 0.0001 (0)
1: infsum = 0 (0)
* 1: objval = 0.0001 (0)
* 1: objval = 0.0001 (0)
OPTIMAL SOLUTION FOUND
Time used: 0.0 secs
Memory used: 0.1 Mb (92819 bytes)
Display statement at line 14
x.val = 0.0001
x = 0.0001000000000000
Display statement at line 17
delta_min = 0.0001
Display statement at line 18
delta_max = 0.0002
Model has been successfully processed
Thanks for your help!
Att,
Thiago Henrique Neves
--
Thiago H. Neves
(31) 98608-0666
statement_test_0.001.dat
Description: Binary data
statement_test.mod
Description: MPEG movie
statement_test_0.0001.dat
Description: Binary data
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