use given names in writeLP (#848)

* add option `generic` to writeLP - if true: same behaviour as before with "VAR%d" names - else: try to use given names, replacing some chars with `_` * add test for writeLP(generic=false) * writeLP: rename generic -> genericnames * update doc wrt `writeLP`
jump-dev · Sep 25, 2016 · 9865cd3 · 9865cd3
1 parent 167f349
commit 9865cd3
Show file tree

Hide file tree

Showing 3 changed files with 78 additions and 13 deletions.
diff --git a/doc/refmodel.rst b/doc/refmodel.rst
@@ -65,7 +65,7 @@ Methods
 
 **Output**
 
-* ``writeLP(m::Model, filename::AbstractString)`` - write the model to ``filename`` in the LP file format.
+* ``writeLP(m::Model, filename::AbstractString; genericnames=true)`` - write the model to ``filename`` in the LP file format. Set ``genericnames=false`` for user-defined variable names.
 * ``writeMPS(m::Model, filename::AbstractString)`` - write the model to ``filename`` in the MPS file format.
 
 .. _solvestatus:

diff --git a/src/writers.jl b/src/writers.jl
@@ -175,7 +175,20 @@ end
 # LP File Writer
 # We use the formatting defined at:
 #   http://lpsolve.sourceforge.net/5.0/CPLEX-format.htm
-function writeLP(m::Model, fname::AbstractString)
+
+varname_generic(m::Model, col::Integer) = "VAR$(col)"
+
+function varname_given(m::Model, col::Integer)
+    # TODO: deal with non-ascii characters?
+    name = getname(m, col)
+    for (pat, sub) in [("[", "_"), ("]", ""), (",", "_")]
+        name = replace(name, pat, sub)
+    end
+    name
+end
+
+function writeLP(m::Model, fname::AbstractString; genericnames=true)
+    varname = genericnames ? varname_generic : varname_given
 
     f = open(fname, "w")
 
@@ -198,15 +211,15 @@ function writeLP(m::Model, fname::AbstractString)
         else
             print_shortest(f, abs(objaff.coeffs[ind]))
         end
-        @printf(f, " VAR%d %s ", objaff.vars[ind].col, (objaff.coeffs[ind+1] < 0)? "-" : "+")
+        @printf(f, " %s %s ", varname(m, objaff.vars[ind].col), (objaff.coeffs[ind+1] < 0)? "-" : "+")
     end
     if nnz >= 1
         if nnz == 1
             print_shortest(f, objaff.coeffs[nnz])
         else
             print_shortest(f, abs(objaff.coeffs[nnz]))
         end
-        @printf(f, " VAR%d\n", objaff.vars[nnz].col)
+        @printf(f, " %s\n", varname(m, objaff.vars[nnz].col))
     end
 
     # Constraints
@@ -218,15 +231,15 @@ function writeLP(m::Model, fname::AbstractString)
             else
                 print_shortest(f, abs(c.terms.coeffs[ind]))
             end
-            @printf(f, " VAR%d %s ", c.terms.vars[ind].col, (c.terms.coeffs[ind+1] < 0)? "-" : "+")
+            @printf(f, " %s %s ", varname(m, c.terms.vars[ind].col), (c.terms.coeffs[ind+1] < 0)? "-" : "+")
         end
         if nnz >= 1
             if nnz == 1
                 print_shortest(f, c.terms.coeffs[nnz])
             else
                 print_shortest(f, abs(c.terms.coeffs[nnz]))
             end
-            @printf(f, " VAR%d", c.terms.vars[nnz].col)
+            @printf(f, " %s", varname(m, c.terms.vars[nnz].col))
         end
     end
     write(f,"Subject To\n")
@@ -274,10 +287,10 @@ function writeLP(m::Model, fname::AbstractString)
             # No low bound
             if m.colUpper[i] == +Inf
                 # Free
-                @printf(f, " VAR%d free\n", i)
+                @printf(f, " %s free\n", varname(m, i))
             else
                 # x <= finite
-                @printf(f, " -inf <= VAR%d <= ", i)
+                @printf(f, " -inf <= %s <= ", varname(m, i))
                 print_shortest(f, m.colUpper[i])
                 println(f)
             end
@@ -287,12 +300,12 @@ function writeLP(m::Model, fname::AbstractString)
                 # x >= finite
                 @printf(f, " ")
                 print_shortest(f, m.colLower[i])
-                @printf(f," <= VAR%d <= +inf\n", i)
+                @printf(f," <= %s <= +inf\n", varname(m, i))
             else
                 # finite <= x <= finite
                 @printf(f, " ")
                 print_shortest(f, m.colLower[i])
-                @printf(f, " <= VAR%d <= ", i)
+                @printf(f, " <= %s <= ", varname(m, i))
                 print_shortest(f, m.colUpper[i])
                 println(f)
             end
@@ -305,7 +318,7 @@ function writeLP(m::Model, fname::AbstractString)
         t = m.colCat[i]
         (t == :SemiCont || t == :SemiInt) && error("The LP file writer does not currently support semicontinuous or semi-integer variables")
         if t == :Bin || t == :Int
-            @printf(f, " VAR%d\n", i)
+            @printf(f, " %s\n", varname(m, i))
         end
     end
 

diff --git a/test/model.jl b/test/model.jl
@@ -73,8 +73,60 @@ facts("[model] Test printing a model") do
     constraints[2] = @constraint(modA, sum{r[i],i=3:5} <= (2 - x)/2.0)
     constraints[3] = @constraint(modA, 6y + y <= z + r[6]/1.9)
     #####################################################################
-    # Test LP writer
-    writeLP(modA, modPath * "A.lp")
+    # Test LP writer (given names)
+    writeLP(modA, modPath * "A.lp", genericnames=false)
+    modALP = if VERSION >= v"0.5.0-dev+1866" # leading zero, base Julia PR #14377
+        String[
+        "Maximize",
+        "obj: 0.16666666666666666 col_1 + 0.16666666666666666 y + 1 z + 1 r_3",
+        "Subject To",
+        "c1: 1 col_1 + 1 y >= 2",
+        "c2: 1 col_1 + 1 y <= 4",
+        "c3: 1 r_3 + 1 r_4 + 1 r_5 + 0.5 col_1 <= 1",
+        "c4: 6 y + 1 y - 1 z - 0.5263157894736842 r_6 <= 0",
+        "Bounds",
+        "0 <= col_1 <= +inf",
+        "-inf <= y <= 5",
+        "2 <= z <= 4",
+        "0 <= r_3 <= 3",
+        "0 <= r_4 <= 4",
+        "0 <= r_5 <= 5",
+        "0 <= r_6 <= 6",
+        "General",
+        "y",
+        "End"]
+    else
+        String[
+        "Maximize",
+        "obj: .16666666666666666 col_1 + .16666666666666666 y + 1 z + 1 r_3",
+        "Subject To",
+        "c1: 1 col_1 + 1 y >= 2",
+        "c2: 1 col_1 + 1 y <= 4",
+        "c3: 1 r_3 + 1 r_4 + 1 r_5 + .5 col_1 <= 1",
+        "c4: 6 y + 1 y - 1 z - .5263157894736842 r_6 <= 0",
+        "Bounds",
+        "0 <= col_1 <= +inf",
+        "-inf <= y <= 5",
+        "2 <= z <= 4",
+        "0 <= r_3 <= 3",
+        "0 <= r_4 <= 4",
+        "0 <= r_5 <= 5",
+        "0 <= r_6 <= 6",
+        "General",
+        "y",
+        "End"]
+    end
+    modAfp = open(modPath * "A.lp")
+    lineInd = 1
+    while !eof(modAfp)
+        line = readline(modAfp)
+        @fact strip(line) --> strip(modALP[lineInd])
+        lineInd += 1
+    end
+    close(modAfp)
+    #####################################################################
+    # Test LP writer (generic names)
+    writeLP(modA, modPath * "A.lp", genericnames=true)
     modALP = if VERSION >= v"0.5.0-dev+1866" # leading zero, base Julia PR #14377
         String[
         "Maximize",