fix #100

js/module/array2d.js

@@ -136,7 +136,7 @@ Array2DTracer.prototype = $.extend(true, Object.create(Tracer.prototype), {
   processStep: function (step, options) {
     switch (step.type) {
       case 'notify':
-        if (step.v === 0 || step.v) {
+        if (step.v !== undefined) {
           var $row = this.$table.find('.mtbl-row').eq(step.x);
           var $col = $row.find('.mtbl-col').eq(step.y);
           $col.text(refineByType(step.v));

js/module/chart.js

@@ -75,7 +75,7 @@ ChartTracer.prototype = $.extend(true, Object.create(Tracer.prototype), {
   processStep: function (step, options) {
     switch (step.type) {
       case 'notify':
-        if (step.v) {
+        if (step.v !== undefined) {
           this.chart.config.data.datasets[0].data[step.s] = step.v;
           this.chart.config.data.labels[step.s] = step.v.toString();
         }