collapse columns fix

src/io/txt_reader.js

-morpheus.TxtReader = function(options) {
+morpheus.TxtReader = function (options) {
 	this.options = $.extend({}, {
-		dataRowStart : 1,
-		dataColumnStart : 1
+		dataRowStart: 1,
+		dataColumnStart: 1
 	}, options);
 };
 morpheus.TxtReader.prototype = {
-	read : function(fileOrUrl, callback) {
+	read: function (fileOrUrl, callback) {
 		var _this = this;
 		var name = morpheus.Util.getBaseFileName(morpheus.Util
 		.getFileName(fileOrUrl));
-		morpheus.BufferedReader.getArrayBuffer(fileOrUrl, function(err,
+		morpheus.BufferedReader.getArrayBuffer(fileOrUrl, function (err,
 																	arrayBuffer) {
 			if (err) {
 				callback(err);
@@ -25,7 +25,7 @@ morpheus.TxtReader.prototype = {
 		});
 
 	},
-	_read : function(datasetName, reader) {
+	_read: function (datasetName, reader) {
 		var tab = /\t/;
 		var header = morpheus.Util.trim(reader.readLine()).split(tab);
 		if (this.options.dataRowStart > 1) {
@@ -50,7 +50,7 @@ morpheus.TxtReader.prototype = {
 				var tokens = s.split(tab);
 				for (var j = 0; j < dataColumnStart; j++) {
 					// row metadata
-					arrayOfRowArrays[j].push(String(tokens[j]));
+					arrayOfRowArrays[j].push(morpheus.Util.copyString(tokens[j]));
 				}
 				for (var j = dataColumnStart; j <= ncols; j++) {
 					var token = tokens[j];
@@ -59,23 +59,16 @@ morpheus.TxtReader.prototype = {
 			}
 		}
 		var dataset = new morpheus.Dataset({
-			name : datasetName,
-			rows : matrix.length,
-			columns : ncols,
-			array : matrix,
-			dataType : 'Float32'
+			name: datasetName,
+			rows: matrix.length,
+			columns: ncols,
+			array: matrix,
+			dataType: 'Float32'
 		});
-		// if (this.options.trim) {
-		// arrayOfRowArrays.forEach(function(array) {
-		// for (var i = 0, length = array.length; i < length; i++) {
-		// array[i] = $.trim(array[i]);
-		// }
-		// });
-		// }
-		// morpheus.DatasetUtil.fill(dataset, NaN);
+
 		var columnIds = dataset.getColumnMetadata().add('id');
 		for (var i = 0, j = dataColumnStart; i < ncols; i++, j++) {
-			columnIds.setValue(i, String(header[j]));
+			columnIds.setValue(i, morpheus.Util.copyString(header[j]));
 		}
 		var rowIdVector = dataset.getRowMetadata().add('id');
 		rowIdVector.array = arrayOfRowArrays[0];

src/tools/collapse_dataset_tool.js

@@ -57,13 +57,13 @@ morpheus.CollapseDatasetTool.prototype = {
 		var dataset = project.getFullDataset();
 		var rows = options.input.collapse == 'Rows';
 		if (!rows) {
-			dataset = morpheus.DatasetUtil.transposedView(dataset);
+			dataset = new morpheus.TransposedDatasetView(dataset);
 		}
 		var allFields = morpheus.MetadataUtil.getMetadataNames(dataset
 		.getRowMetadata());
 		dataset = morpheus.CollapseDataset(dataset, collapseToFields, f, true);
 		if (!rows) {
-			dataset = dataset.getDataset();
+			dataset = new morpheus.TransposedDatasetView(dataset);
 		}
 		var set = new morpheus.Map();
 		_.each(allFields, function (field) {

src/ui/heat_map_element_canvas.js

@@ -168,9 +168,19 @@ morpheus.HeatMapElementCanvas.prototype = {
 		var right = morpheus.Positions.getRight(clip, columnPositions);
 		var top = morpheus.Positions.getTop(clip, rowPositions);
 		var bottom = morpheus.Positions.getBottom(clip, rowPositions);
+		if (this.dataset.getRowCount() === 0 || this.dataset.getColumnCount() === 0) {
+			return context.fillText("No data", 0, 0);
+		} else {
 			context.translate(-clip.x, -clip.y);
-		this._draw({left: left, right: right, top: top, bottom: bottom, context: context});
+			this._draw({
+				left: left,
+				right: right,
+				top: top,
+				bottom: bottom,
+				context: context
+			});
 			context.translate(clip.x, clip.y);
+		}
 
 	},
 	_draw: function (options) {
@@ -180,6 +190,7 @@ morpheus.HeatMapElementCanvas.prototype = {
 		var bottom = options.bottom;
 		var context = options.context;
 		var dataset = this.dataset;
+
 		var columnPositions = this.columnPositions;
 		var rowPositions = this.rowPositions;