Next: Functions and Variables for simplex, Previous: simplex-pkg, Up: simplex-pkg [Contents][Index]
simplex is a package for linear optimization using the simplex algorithm.
Example:
(%i1) load("simplex")$
(%i2) minimize_lp(x+y, [3*x+2*y>2, x+4*y>3]);
                  9        7       1
(%o2)            [--, [y = --, x = -]]
                  10       10      5
There are some tests in the directory share/simplex/Tests.
The function klee_minty produces input for linear_program, for which
exponential time for solving is required without scaling.
Example:
load("klee_minty")$
apply(linear_program, klee_minty(6));
A better approach:
epsilon_sx : 0$ scale_sx : true$ apply(linear_program, klee_minty(10));
Some smaller problems from netlib (https://www.netlib.org/lp/data/)
test suite are converted to a format, readable by Maxima. Problems are
adlittle, afiro, kb2, sc50a and
share2b. Each problem has three input files in CSV format for
matrix A and vectors b and c.
Example:
A : read_matrix("adlittle_A.csv", 'csv)$
b : read_list("adlittle_b.csv", 'csv)$
c : read_list("adlittle_c.csv", 'csv)$
linear_program(A, b, c)$
%[2];
=> 225494.9631623802
Results:
PROBLEM MINIMUM SCALING adlittle +2.2549496316E+05 false afiro -4.6475314286E+02 false kb2 -1.7499001299E+03 true sc50a -6.4575077059E+01 false share2b -4.1573518187E+02 false
The Netlib website https://www.netlib.org/lp/data/readme lists the values as
PROBLEM MINIMUM adlittle +2.2549496316E+05 afiro -4.6475314286E+02 kb2 -1.7499001299E+03 sc50a -6.4575077059E+01 share2b -4.1573224074E+02
Next: Functions and Variables for simplex, Previous: simplex-pkg, Up: simplex-pkg [Contents][Index]