From: Evert Timberg <evert.timberg@gmail.com>
Date: Wed, 16 Dec 2015 00:18:18 +0000 (-0500)
Subject: Update logarithmic algorithm
X-Git-Tag: 2.0.0-beta2~19^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f51d7753bd3dea42e51487831c3b0f6f732460c1;p=thirdparty%2FChart.js.git

Update logarithmic algorithm
---

diff --git a/src/scales/scale.logarithmic.js b/src/scales/scale.logarithmic.js
index 8694608bb..0de930ae6 100644
--- a/src/scales/scale.logarithmic.js
+++ b/src/scales/scale.logarithmic.js
@@ -10,10 +10,10 @@
 
 		// label settings
 		ticks: {
-			callback: function(value) {
+			callback: function(value, index, arr) {
 				var remain = value / (Math.pow(10, Math.floor(Chart.helpers.log10(value))));
 
-				if (remain === 1 || remain === 2 || remain === 5) {
+				if (remain === 1 || remain === 2 || remain === 5 || index === 0 || index === arr.length - 1) {
 					return value.toExponential();
 				} else {
 					return '';
@@ -90,13 +90,8 @@
 				}, this);
 			}
 
-			if (this.options.ticks.max) {
-				this.max = this.options.ticks.max;
-			}
-
-			if (this.options.ticks.min) {
-				this.min = this.options.ticks.min;
-			}
+			this.min = this.options.ticks.min !== undefined ? this.options.ticks.min : this.min;
+			this.max = this.options.ticks.max !== undefined ? this.options.ticks.max : this.max;
 
 			if (this.min === this.max) {
 				if (this.min !== 0 && this.min !== null) {
@@ -118,24 +113,37 @@
 			// We also limit the maximum number of ticks to 11 which gives a nice 10 squares on 
 			// the graph
 
-			var minExponent = Math.floor(helpers.log10(this.min));
-			var maxExponent = Math.ceil(helpers.log10(this.max));
+			var tickVal = this.options.ticks.min !== undefined ? this.options.ticks.min : Math.pow(10, Math.floor(helpers.log10(this.min)));
 
-			for (var exponent = minExponent; exponent < maxExponent; ++exponent) {
-				for (var i = 1; i < 10; ++i) {
-					this.tickValues.push(i * Math.pow(10, exponent));
+			while (tickVal < this.max) {
+				this.tickValues.push(tickVal);
+
+				var exp = Math.floor(helpers.log10(tickVal));
+				var significand = Math.floor(tickVal / Math.pow(10, exp)) + 1;
+
+				if (significand === 10) {
+					significand = 1;
+					++exp;
 				}
+
+				tickVal = significand * Math.pow(10, exp);
 			}
 
-			this.tickValues.push(1.0 * Math.pow(10, maxExponent));
+			/*var minExponent = Math.floor(helpers.log10(this.min));
+			var maxExponent = Math.ceil(helpers.log10(this.max));
 
-			if (this.options.ticks.min) {
-				this.tickValues[0] = this.min;
-			}
+			for (var exponent = minExponent; exponent < maxExponent; ++exponent) {
+				for (var i = 1; i < 10; ++i) {
+					if (this.options.ticks.min) {
 
-			if (this.options.ticks.max) {
-				this.tickValues[this.tickValues.length - 1] = this.max;
-			}
+					} else {
+						this.tickValues.push(i * Math.pow(10, exponent));
+					}
+				}
+			}*/
+
+			var lastTick = this.options.ticks.max !== undefined ? this.options.ticks.max : tickVal;
+			this.tickValues.push(lastTick);
 
 			if (this.options.position == "left" || this.options.position == "right") {
 				// We are in a vertical orientation. The top value is the highest. So reverse the array
@@ -147,14 +155,6 @@
 			this.max = helpers.max(this.tickValues);
 			this.min = helpers.min(this.tickValues);
 
-			if (this.options.ticks.min) {
-				this.min = this.options.ticks.min;
-			}
-
-			if (this.options.ticks.max) {
-				this.max = this.options.ticks.max;
-			}
-
 			if (this.options.ticks.reverse) {
 				this.tickValues.reverse();