fix sparse matrix write

Author: renkekuhlmann

+gams/+transfer/+gdx/gt_gdx_write.cpp

@@ -493,6 +493,8 @@ void mexFunction(
                 {
                     for (size_t k = 0; k < sizes[1]; k++)
                     {
+                        bool is_default_rec = true;
+
                         /* set domains */
                         if (dim >= 1)
                             gdx_uel_index[0] = domain_uel_ids[0][j];
@@ -507,13 +509,16 @@ void mexFunction(
                                 continue;
                             idx = mx_cols[kk][k] + col_nnz[kk][k];
                             if (idx >= mx_cols[kk][k+1] || mx_rows[kk][idx] != j)
-                            {
                                 gdx_values[kk] = 0;
-                                continue;
+                            else
+                            {
+                                col_nnz[kk][k]++;
+                                gdx_values[kk] = gt_utils_sv_matlab2gams(mx_values[kk][idx], eps_to_zero);
                             }
-                            col_nnz[kk][k]++;
-                            gdx_values[kk] = gt_utils_sv_matlab2gams(mx_values[kk][idx], eps_to_zero);
+                            is_default_rec = (gdx_values[kk] != def_values[kk]) ? false : is_default_rec;
                         }
+                        if (can_skip_default_recs && is_default_rec)
+                            continue;
 
                         /* write values */
                         if (issorted)

CHANGELOG.md

@@ -1,3 +1,7 @@
+GAMS Transfer Matlab v1.0.3
+==================
+- Fixed sparse write of format `sparse_matrix`.
+
 GAMS Transfer Matlab v1.0.2
 ==================
 - Fixed GDX setup.

test/test_readwrite.m

@@ -38,6 +38,7 @@
     test_readWriteCompress(t, cfg);
     test_readWriteDomainCheck(t, cfg);
     test_writeEpsToZero(t, cfg);
+    test_writeSparse(t, cfg);
     [~, n_fails1] = t.summary();
 
     t = GAMSTest('readwrite_rc');
@@ -1738,3 +1739,28 @@ function test_writeEpsToZero(t, cfg)
     t.assert(gams.transfer.SpecialValues.isEps(gdx.data.e.records.scale));
 
 end
+
+function test_writeSparse(t, cfg)
+
+    gdx = gams.transfer.Container();
+    i = gams.transfer.Set(gdx, 'i', '*', 'records', {'i1', 'i2', 'i3', 'i4', 'i5', 'i6', 'i7', 'i8', 'i9', 'i10'});
+    gams.transfer.Parameter(gdx, 'p', i, 'records', {{'i2', 'i6'}, [2 6]});
+
+    t.add('write_sparse_sparse_matrix');
+    gdx.data.p.transformRecords('sparse_matrix');
+    gdx.write('test.gdx');
+    t.assert(~system(sprintf('gdxdump %s Symbols | grep -q "p *1 *Par *2"', 'test.gdx')));
+
+    t.add('write_sparse_struct');
+    gdx.data.p.transformRecords('struct');
+    gdx.write('test.gdx');
+    t.assert(~system(sprintf('gdxdump %s Symbols | grep -q "p *1 *Par *2"', 'test.gdx')));
+
+    if gams.transfer.Constants.SUPPORTS_TABLE
+        t.add('write_sparse_table');
+        gdx.data.p.transformRecords('table');
+        gdx.write('test.gdx');
+        t.assert(~system(sprintf('gdxdump %s Symbols | grep -q "p *1 *Par *2"', 'test.gdx')));
+    end
+
+end