standardize the extra we add to contours to avoid rounding errors

alexcjohnson · alexcjohnson · commit 4f5de76791f7 · 2017-01-17T23:21:31.000-05:00
this avoids an edge case where the colorbar and the colorscale got
out of sync or did not end at the same place
diff --git a/src/traces/contour/colorbar.js b/src/traces/contour/colorbar.js
@@ -13,6 +13,7 @@ var Plots = require('../../plots/plots');
 var drawColorbar = require('../../components/colorbar/draw');
 
 var makeColorMap = require('./make_color_map');
+var endPlus = require('./end_plus');
 
 
 module.exports = function colorbar(gd, cd) {
@@ -52,7 +53,7 @@ module.exports = function colorbar(gd, cd) {
         })
         .levels({
             start: contours.start,
-            end: contours.end,
+            end: endPlus(contours),
             size: cs
         })
         .options(trace.colorbar)();
diff --git a/src/traces/contour/end_plus.js b/src/traces/contour/end_plus.js
@@ -0,0 +1,18 @@
+/**
+* Copyright 2012-2017, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+
+'use strict';
+
+/*
+ * tiny helper to move the end of the contours a little to prevent
+ * losing the last contour to rounding errors
+ */
+module.exports = function endPlus(contours) {
+    return contours.end + contours.size / 1e6;
+};
diff --git a/src/traces/contour/make_color_map.js b/src/traces/contour/make_color_map.js
@@ -11,13 +11,14 @@
 
 var d3 = require('d3');
 var Colorscale = require('../../components/colorscale');
+var endPlus = require('./end_plus');
 
 module.exports = function makeColorMap(trace) {
     var contours = trace.contours,
         start = contours.start,
-        end = contours.end,
+        end = endPlus(contours),
         cs = contours.size || 1,
-        nc = Math.floor((end + cs / 10 - start) / cs) + 1,
+        nc = Math.floor((end - start) / cs) + 1,
         extra = contours.coloring === 'lines' ? 0 : 1;
 
     var scl = trace.colorscale,
diff --git a/src/traces/contour/plot.js b/src/traces/contour/plot.js
@@ -17,6 +17,7 @@ var Drawing = require('../../components/drawing');
 var heatmapPlot = require('../heatmap/plot');
 var makeCrossings = require('./make_crossings');
 var findAllPaths = require('./find_all_paths');
+var endPlus = require('./end_plus');
 
 
 module.exports = function plot(gd, plotinfo, cdcontours) {
@@ -81,9 +82,10 @@ function plotOne(gd, plotinfo, cd) {
 
 function emptyPathinfo(contours, plotinfo, cd0) {
     var cs = contours.size,
-        pathinfo = [];
+        pathinfo = [],
+        end = endPlus(contours);
 
-    for(var ci = contours.start; ci < contours.end + cs / 10; ci += cs) {
+    for(var ci = contours.start; ci < end; ci += cs) {
         pathinfo.push({
             level: ci,
             // all the cells with nontrivial marching index
diff --git a/src/traces/contour/style.js b/src/traces/contour/style.js
@@ -34,11 +34,11 @@ module.exports = function style(gd) {
 
         var colorMap = makeColorMap(trace);
 
-        c.selectAll('g.contourlevel').each(function(d, i) {
+        c.selectAll('g.contourlevel').each(function(d) {
             d3.select(this).selectAll('path')
                 .call(Drawing.lineGroupStyle,
                     line.width,
-                    contours.coloring === 'lines' ? colorMap(start + i * cs) : line.color,
+                    contours.coloring === 'lines' ? colorMap(d.level) : line.color,
                     line.dash);
         });
 
