Sage Reference Manual: Numerical Optimization - Mirrors

Sage Reference Manual: Numerical Optimization, Release 6.1.1
•fname – full name of the file
OUTPUT:
Zero if the operations was successful otherwise nonzero
EXAMPLE:
sage: from sage.numerical.backends.glpk_graph_backend import GLPKGraphBackend
sage: gbe = GLPKGraphBackend()
sage: a = gbe.add_edge("0", "1")
sage: gbe.write_ccdata(SAGE_TMP+"/graph.dat")
Writing graph to ...
6 lines were written
0
write_graph(fname)
Writes the graph to a plain text file
INPUT:
•fname – full name of the file
OUTPUT:
Zero if the operations was successful otherwise nonzero
EXAMPLE:
sage: from sage.numerical.backends.glpk_graph_backend import GLPKGraphBackend
sage: gbe = GLPKGraphBackend()
sage: a = gbe.add_edge("0", "1")
sage: gbe.write_graph(SAGE_TMP+"/graph.txt")
Writing graph to ...
2 lines were written
0
write_maxflow(fname)
Writes the maximum flow problem data to a text file in DIMACS format.
INPUT:
•fname – Full name of file
OUTPUT:
Zero if successful, otherwise non-zero
EXAMPLE:
sage: from sage.numerical.backends.glpk_graph_backend import GLPKGraphBackend
sage: gbe = GLPKGraphBackend()
sage: gbe.add_vertices([None for i in range(2)])
[’0’, ’1’]
sage: a = gbe.add_edge(’0’, ’1’)
sage: gbe.maxflow_ffalg(’0’, ’1’)
0.0
sage: gbe.write_maxflow(SAGE_TMP+"/graph.max")
Writing maximum flow problem data to ...
6 lines were written
0
sage: gbe = GLPKGraphBackend()
sage: gbe.write_maxflow(SAGE_TMP+"/graph.max")
Traceback (most recent call last):
5.3. GLPK Backend for access to GLPK graph functions 91