support non-numeric y-axis values and single series timelines

example.html

@@ -114,4 +114,33 @@
       });
     });
   </script>
+  
+  <h3>Text values</h3>
+  <div id="graph-yyyy-mm-dd" class="graph" style="height:175px"></div>
+  <script>
+    $(function () {
+      // data from https://en.wikipedia.org/wiki/United_States_presidential_election,_2012_timeline
+      var day_data = [
+        {"period": "2012-01-03", "event": "Iowa"},
+        {"period": "2012-01-10", "event": "New Hampshire"},
+        {"period": "2012-01-21", "event": "South Carolina"},
+        {"period": "2012-01-31", "event": "Florida"},
+        {"period": "2012-02-04", "event": "Maine, Nevada"},
+        {"period": "2012-02-07", "event": "Colorado, Minnesota, Missouri"},
+        {"period": "2012-02-28", "event": "Arizona, Michigan"},
+        {"period": "2012-02-29", "event": "Wyoming"},
+        {"period": "2012-03-01", "event": "Washington"},
+        {"period": "2012-03-06", "event": "Super Tuesday"},
+      ];
+      Morris.Line({
+        element: 'graph-yyyy-mm-dd',
+        data: day_data,
+        xkey: 'period',
+        ykeys: ['event'],
+        labels: ['event'],
+		marginBottom: 100,
+		numLines: 1
+      });
+    });
+  </script>  
 </body>

morris.coffee

@@ -95,6 +95,9 @@ class Morris.Line
     # remove child elements (get rid of old drawings)
     @el.empty()
 
+    isNumber = (o) =>
+      ! isNan (o-0)
+
     # the raphael drawing instance
     @r = new Raphael(@el[0])
 
@@ -103,7 +106,7 @@ class Morris.Line
     width = @el.width() - left - @options.marginRight
     height = @el.height() - @options.marginTop - @options.marginBottom
     dx = width / (@xmax - @xmin)
-    dy = height / @options.ymax
+    dy = height / (if isNumber(@options.ymax) then @options.ymax else height)
 
     # quick translation helpers
     transX = (x) =>
@@ -112,13 +115,15 @@ class Morris.Line
       else
        left + (x - @xmin) * dx
     transY = (y) =>
-      return @options.marginTop + height - y * dy
+      return @options.marginTop + height - (if isNumber(y) then y * dy else dy)
 
     # draw y axis labels, horizontal lines
-    lineInterval = height / (@options.numLines - 1)
+    lineInterval = height / (if @options.numLines == 1 then 2 else (@options.numLines - 1))
     for i in [0..@options.numLines-1]
       y = @options.marginTop + i * lineInterval
-      v = Math.round((@options.numLines - 1 - i) * @options.ymax / (@options.numLines - 1))
+      v = Math.round((@options.numLines - 1 - i) * @options.ymax / (if @options.numLines == 1 then 1 else (@options.numLines - 1)))
+      if isNaN(v)
+        v = ""
       @r.text(left - @options.marginLeft/2, y, v)
         .attr('font-size', @options.gridTextSize)
         .attr('fill', @options.gridTextColor)
@@ -187,7 +192,7 @@ class Morris.Line
       hoverSet.show()
       xLabel.attr('text', @columnLabels[index])
       for i in [0..@series.length-1]
-        yLabels[i].attr('text', "#{@seriesLabels[i]}: #{@commas(@series[i][index])}")
+        yLabels[i].attr('text', "#{@seriesLabels[i]}: #{if isNumber(@series[i][index]) then @commas(@series[i][index]) else @series[i][index]}")
       # recalculate hover box width
       maxLabelWidth = Math.max.apply null, $.map yLabels, (l) ->
         l.getBBox().width

morris.js

@@ -85,15 +85,18 @@
     };
 
     Line.prototype.redraw = function() {
-      var c, circle, columns, coords, dx, dy, height, hideHover, hilight, hover, hoverHeight, hoverMargins, hoverSet, i, label, labelBox, left, lineInterval, path, pointGrow, pointShrink, prevHilight, prevLabelMargin, s, seriesCoords, seriesPoints, touchHandler, transX, transY, updateHilight, updateHover, v, width, x, xLabel, xLabelMargin, y, yLabel, yLabels, _i, _j, _len, _len2, _ref, _ref2, _ref3, _ref4, _ref5, _ref6, _ref7, _ref8,
+      var c, circle, columns, coords, dx, dy, height, hideHover, hilight, hover, hoverHeight, hoverMargins, hoverSet, i, isNumber, label, labelBox, left, lineInterval, path, pointGrow, pointShrink, prevHilight, prevLabelMargin, s, seriesCoords, seriesPoints, touchHandler, transX, transY, updateHilight, updateHover, v, width, x, xLabel, xLabelMargin, y, yLabel, yLabels, _i, _j, _len, _len2, _ref, _ref2, _ref3, _ref4, _ref5, _ref6, _ref7, _ref8,
         _this = this;
       this.el.empty();
+      isNumber = function(o) {
+        return !isNan(o - 0);
+      };
       this.r = new Raphael(this.el[0]);
       left = this.measureText(this.options.ymax, this.options.gridTextSize).width + this.options.marginLeft;
       width = this.el.width() - left - this.options.marginRight;
       height = this.el.height() - this.options.marginTop - this.options.marginBottom;
       dx = width / (this.xmax - this.xmin);
-      dy = height / this.options.ymax;
+      dy = height / (isNumber(this.options.ymax) ? this.options.ymax : height);
       transX = function(x) {
         if (_this.xvals.length === 1) {
           return left + width / 2;
@@ -102,12 +105,13 @@
         }
       };
       transY = function(y) {
-        return _this.options.marginTop + height - y * dy;
+        return _this.options.marginTop + height - (isNumber(y) ? y * dy : dy);
       };
-      lineInterval = height / (this.options.numLines - 1);
+      lineInterval = height / (this.options.numLines === 1 ? 2 : this.options.numLines - 1);
       for (i = 0, _ref = this.options.numLines - 1; 0 <= _ref ? i <= _ref : i >= _ref; 0 <= _ref ? i++ : i--) {
         y = this.options.marginTop + i * lineInterval;
-        v = Math.round((this.options.numLines - 1 - i) * this.options.ymax / (this.options.numLines - 1));
+        v = Math.round((this.options.numLines - 1 - i) * this.options.ymax / (this.options.numLines === 1 ? 1 : this.options.numLines - 1));
+        if (isNaN(v)) v = "";
         this.r.text(left - this.options.marginLeft / 2, y, v).attr('font-size', this.options.gridTextSize).attr('fill', this.options.gridTextColor).attr('text-anchor', 'end');
         this.r.path("M" + left + "," + y + 'H' + (left + width)).attr('stroke', this.options.gridLineColor).attr('stroke-width', this.options.gridStrokeWidth);
       }
@@ -183,7 +187,7 @@
         hoverSet.show();
         xLabel.attr('text', _this.columnLabels[index]);
         for (i = 0, _ref9 = _this.series.length - 1; 0 <= _ref9 ? i <= _ref9 : i >= _ref9; 0 <= _ref9 ? i++ : i--) {
-          yLabels[i].attr('text', "" + _this.seriesLabels[i] + ": " + (_this.commas(_this.series[i][index])));
+          yLabels[i].attr('text', "" + _this.seriesLabels[i] + ": " + (isNumber(_this.series[i][index]) ? _this.commas(_this.series[i][index]) : _this.series[i][index]));
         }
         maxLabelWidth = Math.max.apply(null, $.map(yLabels, function(l) {
           return l.getBBox().width;