update pivot calculation.

resources/frontend_client/app/lib/data_grid.js

@@ -7,60 +7,67 @@ var DataGrid = {
         // find the lowest cardinality dimension and make it our "pivoted" column
         // TODO: we assume dimensions are in the first 2 columns, which is less than ideal
         var pivotCol = 0,
-        	normalCol = 1,
-        	pivotColValues = DataGrid.distinctValues(data, pivotCol);
-        if (DataGrid.cardinality(data, 1) <= pivotColValues.length) {
-        	pivotCol = 1;
-        	normalCol = 0;
-        	pivotColValues = DataGrid.distinctValues(data, pivotCol);
+            normalCol = 1,
+            pivotColValues = DataGrid.distinctValues(data, pivotCol),
+            normalColValues = DataGrid.distinctValues(data, normalCol);
+        if (normalColValues.length <= pivotColValues.length) {
+            pivotCol = 1;
+            normalCol = 0;
+
+            var tmp = pivotColValues;
+            pivotColValues = normalColValues;
+            normalColValues = tmp;
         }
 
-        // sort the pivot column values sensibly
+        // sort the column values sensibly
         pivotColValues.sort();
-        pivotColValues.unshift(null);
+        normalColValues.sort();
 
-        // build the pivoted data grid
-        var values = data.rows.reduce(function(last, now) {
-        	// grab the last "row" from the total dataset (if possible)
-        	var row = (last.length > 0) ? last[last.length - 1] : null;
-        	if (row === null || row[0] !== now[normalCol]) {
-        		row = Array.apply(null, Array(pivotColValues.length)).map(function() { return null; });
-        		row[0] = now[normalCol];
-        		last.push(row);
-        	}
+        // make sure that the first element in the pivoted column list is null which makes room for the label of the other column
+        pivotColValues.unshift(null);
 
-    		// put current value into the result at the correct pivoted index
-    		// TODO: we are hard coding to the 3rd value here, assuming that is always the metric :/
-    		row[pivotColValues.lastIndexOf(now[pivotCol])] = now[2];
+        // start with an empty grid that we'll fill with the appropriate values
+        var pivotedRows = [];
+        var emptyRow = Array.apply(null, Array(pivotColValues.length)).map(function() { return null; });
+        for (var i=0; i < normalColValues.length; i++) {
+            pivotedRows.push(_.clone(emptyRow));
+        }
 
-    		return last;
+        // fill it up with the data
+        for (var j=0; j < data.rows.length; j++) {
+            var normalColIdx = normalColValues.lastIndexOf(data.rows[j][normalCol]);
+            var pivotColIdx = pivotColValues.lastIndexOf(data.rows[j][pivotCol]);
 
-        }, []);
+            pivotedRows[normalColIdx][0] = data.rows[j][normalCol];
+            // NOTE: we are hard coding the expectation that the metric is in the 3rd column
+            pivotedRows[normalColIdx][pivotColIdx] = data.rows[j][2];
+        }
 
+        // provide some column metadata to maintain consistency
         var cols = pivotColValues.map(function(val) {
-        	var colDef = _.clone(data.cols[pivotCol]);
-        	colDef['display_name'] = val || "";
-        	colDef['name'] = val || "";
-        	return colDef;
+            var colDef = _.clone(data.cols[pivotCol]);
+            colDef['display_name'] = val || "";
+            colDef['name'] = val || "";
+            return colDef;
         });
 
         return {
-        	cols: cols,
-        	columns: pivotColValues,
-        	rows: values
+            cols: cols,
+            columns: pivotColValues,
+            rows: pivotedRows
         };
     },
 
     distinctValues: function(data, colIdx) {
-    	var vals = data.rows.map(function(r) {
-    		return r[colIdx];
-    	});
+        var vals = data.rows.map(function(r) {
+            return r[colIdx];
+        });
 
-    	return vals.filter(function(v, i) { return i==vals.lastIndexOf(v); });
+        return vals.filter(function(v, i) { return i==vals.lastIndexOf(v); });
     },
 
     cardinality: function(data, colIdx) {
-    	return DataGrid.distinctValues(data, colIdx).length;
+        return DataGrid.distinctValues(data, colIdx).length;
     }
 };