fix bug in toDomCoords

[dygraphs.git] / dygraph.js

diff --git a/dygraph.js b/dygraph.js
index b009c77..6bacea2 100644 (file)
--- a/dygraph.js
+++ b/dygraph.js
@@ -280,6 +280,55 @@ Dygraph.prototype.xAxisRange = function() {
   return [left, right];
 };
 
+/**
+ * Returns the currently-visible y-range. This can be affected by zooming,
+ * panning or a call to updateOptions.
+ * Returns a two-element array: [bottom, top].
+ */
+Dygraph.prototype.yAxisRange = function() {
+  return this.displayedYRange_;
+};
+
+/**
+ * Convert from data coordinates to canvas/div X/Y coordinates.
+ * Returns a two-element array: [X, Y]
+ */
+Dygraph.prototype.toDomCoords = function(x, y) {
+  var ret = [null, null];
+  var area = this.plotter_.area;
+  if (x !== null) {
+    var xRange = this.xAxisRange();
+    ret[0] = area.x + (x - xRange[0]) / (xRange[1] - xRange[0]) * area.w;
+  }
+
+  if (y !== null) {
+    var yRange = this.yAxisRange();
+    ret[1] = area.y + (yRange[1] - y) / (yRange[1] - yRange[0]) * area.h;
+  }
+
+  return ret;
+};
+
+/**
+ * Convert from canvas/div coords to data coordinates.
+ * Returns a two-element array: [X, Y]
+ */
+Dygraph.prototype.toDataCoords = function(x, y) {
+  var ret = [null, null];
+  var area = this.plotter_.area;
+  if (x !== null) {
+    var xRange = this.xAxisRange();
+    ret[0] = xRange[0] + (x - area.x) / area.w * (xRange[1] - xRange[0]);
+  }
+
+  if (y !== null) {
+    var yRange = this.yAxisRange();
+    ret[1] = yRange[0] + (area.h - y) / area.h * (yRange[1] - yRange[0]);
+  }
+
+  return ret;
+};
+
 Dygraph.addEvent = function(el, evt, fn) {
   var normed_fn = function(e) {
     if (!e) var e = window.event;
@@ -408,9 +457,11 @@ Dygraph.prototype.destroy = function() {
  * @private
  */
 Dygraph.prototype.createPlotKitCanvas_ = function(canvas) {
-  // var h = document.createElement("canvas");
   var h = Dygraph.createCanvas();
   h.style.position = "absolute";
+  // TODO(danvk): h should be offset from canvas. canvas needs to include
+  // some extra area to make it easier to zoom in on the far left and far
+  // right. h needs to be precisely the plot area, so that clipping occurs.
   h.style.top = canvas.style.top;
   h.style.left = canvas.style.left;
   h.width = this.width_;
@@ -1360,7 +1411,6 @@ Dygraph.prototype.drawGraph_ = function(data) {
   var stacked_datasets = [];
 
   // Loop over all fields in the dataset
-
   for (var i = 1; i < data[0].length; i++) {
     if (!this.visibility()[i - 1]) continue;
 
@@ -1372,16 +1422,31 @@ Dygraph.prototype.drawGraph_ = function(data) {
     series = this.rollingAverage(series, this.rollPeriod_);
 
     // Prune down to the desired range, if necessary (for zooming)
+    // Because there can be lines going to points outside of the visible area,
+    // we actually prune to visible points, plus one on either side.
     var bars = this.attr_("errorBars") || this.attr_("customBars");
     if (this.dateWindow_) {
       var low = this.dateWindow_[0];
       var high= this.dateWindow_[1];
       var pruned = [];
+      // TODO(danvk): do binary search instead of linear search.
+      // TODO(danvk): pass firstIdx and lastIdx directly to the renderer.
+      var firstIdx = null, lastIdx = null;
       for (var k = 0; k < series.length; k++) {
-        if (series[k][0] >= low && series[k][0] <= high) {
-          pruned.push(series[k]);
+        if (series[k][0] >= low && firstIdx === null) {
+          firstIdx = k;
+        }
+        if (series[k][0] <= high) {
+          lastIdx = k;
         }
       }
+      if (firstIdx === null) firstIdx = 0;
+      if (firstIdx > 0) firstIdx--;
+      if (lastIdx === null) lastIdx = series.length - 1;
+      if (lastIdx < series.length - 1) lastIdx++;
+      for (var k = firstIdx; k <= lastIdx; k++) {
+        pruned.push(series[k]);
+      }
       series = pruned;
     }
 
@@ -1430,6 +1495,7 @@ Dygraph.prototype.drawGraph_ = function(data) {
   // set explicitly by the user.
   if (this.valueRange_ != null) {
     this.addYTicks_(this.valueRange_[0], this.valueRange_[1]);
+    this.displayedYRange_ = this.valueRange_;
   } else {
     // This affects the calculation of span, below.
     if (this.attr_("includeZero") && minY > 0) {
@@ -1453,6 +1519,7 @@ Dygraph.prototype.drawGraph_ = function(data) {
     }
 
     this.addYTicks_(minAxisY, maxAxisY);
+    this.displayedYRange_ = [minAxisY, maxAxisY];
   }
 
   this.addXTicks_();
@@ -1805,8 +1872,9 @@ Dygraph.prototype.parseArray_ = function(data) {
         return null;
       }
       if (parsedData[i][0] == null
-          || typeof(parsedData[i][0].getTime) != 'function') {
-        this.error("x value in row " << (1 + i) << " is not a Date");
+          || typeof(parsedData[i][0].getTime) != 'function'
+          || isNaN(parsedData[i][0].getTime())) {
+        this.error("x value in row " + (1 + i) + " is not a Date");
         return null;
       }
       parsedData[i][0] = parsedData[i][0].getTime();