From 528e652985798bca825bf1fed09edfe42a4037ee Mon Sep 17 00:00:00 2001
From: Miles Lubin <miles.lubin@gmail.com>
Date: Fri, 10 Apr 2015 22:01:49 -0400
Subject: [PATCH] handle duplicates in MPS writer, fixes #424

---
 src/writers.jl | 23 +++++++++++------------
 test/model.jl  |  6 +++---
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/src/writers.jl b/src/writers.jl
index a217e7e0b60..8661ba20364 100644
--- a/src/writers.jl
+++ b/src/writers.jl
@@ -6,7 +6,7 @@
 function writeMPS(m::Model, fname::String)
     f = open(fname, "w")
 
-    write(f,"NAME   MathProgModel\n")
+    write(f,"NAME   JuMPModel\n")
 
     numRows = length(m.linconstr)
 
@@ -47,31 +47,30 @@ function writeMPS(m::Model, fname::String)
 
 
     nnz += length(objaff.coeffs)
-    colval = Array(Int,nnz)
-    rownzval = Array(Float64,nnz)
+    I = Array(Int,nnz)
+    J = Array(Int,nnz)
+    V = Array(Float64,nnz)
     nnz = 0
     for c in 1:numRows
-        rowptr[c] = nnz + 1
         # TODO: type assertion shouldn't be necessary
         constr::LinearConstraint = m.linconstr[c]
         coeffs = constr.terms.coeffs
         vars = constr.terms.vars
         for ind in 1:length(coeffs)
             nnz += 1
-            colval[nnz] = vars[ind].col
-            rownzval[nnz] = coeffs[ind]
+            I[nnz] = c
+            J[nnz] = vars[ind].col
+            V[nnz] = coeffs[ind]
         end
     end
-    rowptr[numRows+1] = nnz + 1
     for ind in 1:length(objaff.coeffs)
         nnz += 1
-        colval[nnz] = objaff.vars[ind].col
-        rownzval[nnz] = objlincoef[ind]
+        I[nnz] = numRows+1
+        J[nnz] = objaff.vars[ind].col
+        V[nnz] = objlincoef[ind]
     end
-    rowptr[numRows+2] = nnz + 1
 
-    rowmat = SparseMatrixCSC(m.numCols,numRows+1, rowptr, colval, rownzval)
-    colmat = rowmat'
+    colmat = sparse(I,J,V,numRows+1,m.numCols)
     colptr = colmat.colptr
     rowval = colmat.rowval
     nzval = colmat.nzval
diff --git a/test/model.jl b/test/model.jl
index 845f1f656ea..cfde8186848 100644
--- a/test/model.jl
+++ b/test/model.jl
@@ -54,7 +54,7 @@ facts("[model] Test printing a model") do
     @defConstrRef constraints[1:3]
     constraints[1] = @addConstraint(modA, 2 <= x+y <= 4)
     constraints[2] = @addConstraint(modA, sum{r[i],i=3:5} <= (2 - x)/2.0)
-    constraints[3] = @addConstraint(modA, 7.0*y <= z + r[6]/1.9)
+    constraints[3] = @addConstraint(modA, 6y + y <= z + r[6]/1.9)
     #####################################################################
     # Test LP writer
     writeLP(modA, modPath * "A.lp")
@@ -65,7 +65,7 @@ facts("[model] Test printing a model") do
     "c1: 1 VAR1 + 1 VAR2 >= 2",
     "c2: 1 VAR1 + 1 VAR2 <= 4",
     "c3: 1 VAR4 + 1 VAR5 + 1 VAR6 + .5 VAR1 <= 1",
-    "c4: 7 VAR2 - 1 VAR3 - .5263157894736842 VAR7 <= 0",
+    "c4: 6 VAR2 + 1 VAR2 - 1 VAR3 - .5263157894736842 VAR7 <= 0",
     "Bounds",
     "0 <= VAR1 <= +inf",
     "-inf <= VAR2 <= 5",
@@ -89,7 +89,7 @@ facts("[model] Test printing a model") do
     # Test MPS writer
     writeMPS(modA, modPath * "A.mps")
     modAMPS = ASCIIString[
-    "NAME   MathProgModel",
+    "NAME   JuMPModel",
     "ROWS",
     " N  CON4",
     " E  CON1",