two minor model writing/reading bugs in docplex

Two bugs, both minor but worth reporting.

If I build a model with the RHS having float("inf") the .lp that is exported is unreadable.
When I export a model as a .sav file, it doesn't export into the current directory but uses some funny path instead.



In [1]:

    
from docplex.mp.model import Model
from docplex.mp.model_reader import ModelReader



In [2]:

    
m = Model("has an infinity on rhs")
v1 = m.continuous_var(ub = 10, name = "v1")
v2 = m.continuous_var(ub = 10, name = "v2")
m.add_constraint(3*v1 + 2*v2 <= float("inf"))
m.maximize(5*v1 + 4*v2)
print m.solve()









    



solution for: has an infinity on rhs
objective: 90
v1=10.000
v2=10.000



In [3]:

    
file1 = m.export_as_lp("has_infiniy.lp")
file2 = m.export_as_sav("has_infinity.sav")

Bug 1 - the export_as_sav doesn't use the current working directory.



In [4]:

    
import os
os.path.exists(os.path.join(os.getcwd(), "has_infiniy.lp"))









    Out[4]:





True



In [5]:

    
os.path.exists(os.path.join(os.getcwd(), "has_infinity.sav"))









    Out[5]:





False



In [6]:

    
file2









    Out[6]:





'/var/folders/k_/2mp70w997hj84hxfxkwtd_jm0000gn/T/has_infinity.sav'

Bug 2 It can't read the file that was written. The 'inf' is tripping it up.



In [7]:

    
mr =ModelReader()
mr.read_model(file1)









    



*CPLEX error CPLEX Error  1615: Line 8: Expected number, found 'i'.
 reading file has_infiniy.lp - exiting

The save format does work here.



In [8]:

    
m2 = mr.read_model(file2)



In [9]:

    
m2.get_constraint_by_index(0)









    Out[9]:





docplex.mp.linear.LinearConstraint[_c1](3v1+2v2,LE,100000000000000000000)

Just to make this totally clear, if I remove the infinity, then the .lp file writing/reading works.



In [10]:

    
m = Model("no infinity")
v1 = m.continuous_var(ub = 10, name = "v1")
v2 = m.continuous_var(ub = 10, name = "v2")
m.add_constraint(3*v1 + 2*v2 <= 10000)
m.maximize(5*v1 + 4*v2)
print m.solve()









    



solution for: no infinity
objective: 90
v1=10.000
v2=10.000



In [11]:

    
file1 = m.export_as_lp("no_infiniy.lp")



In [12]:

    
m2 = mr.read_model(file1)



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