Improved dot file export for MDPs.

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@1432 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/sparse/PS_ExportMDP.cc

@@ -106,11 +106,15 @@ jstring fn		// filename
 			if (!use_counts) { l2 = choice_starts[j]; h2 = choice_starts[j+1]; }
 			else { l2 = h2; h2 += choice_counts[j]; }
 			if (export_type == EXPORT_ROWS) export_string("%d", i);
+			else if (export_type == EXPORT_DOT) {
+				export_string("%d -> %d.%d [ arrowhead=none,label=\"%d\" ];\n", i, i, j-l1, j-l1);
+				export_string("%d.%d [ shape=circle,width=0.1,height=0.1,label=\"\" ];\n", i, j-l1);
+			}
 			for (k = l2; k < h2; k++) {
 				switch (export_type) {
 				case EXPORT_PLAIN: export_string("%d %d %d %.12g\n", i, j-l1, cols[k], non_zeros[k]); break;
 				case EXPORT_MATLAB: export_string("%s%d(%d,%d)=%.12g;\n", export_name, j-l1+1, i+1, cols[k]+1, non_zeros[k]); break;
-				case EXPORT_DOT: export_string("%d -> %d [ label=\"%d: %.12g\" ];\n", i, cols[k], j-l1, non_zeros[k]); break;
+				case EXPORT_DOT: export_string("%d.%d -> %d [ label=\"%.12g\" ];\n", i, j-l1, cols[k], non_zeros[k]); break;
 				case EXPORT_ROWS: export_string(" %.12g:%d", non_zeros[k], cols[k]); break;
 				}
 			}