From a258aa406d2ba95653befdae2044c8e605ece92b Mon Sep 17 00:00:00 2001
From: Graeme <megawac@gmail.com>
Date: Tue, 25 Nov 2014 18:30:23 -0500
Subject: [PATCH 1/2] Unify [max|min]ValueScale and consider range as the base

---
 smoothie.js | 41 ++++++++++++++++++++---------------------
 1 file changed, 20 insertions(+), 21 deletions(-)

diff --git a/smoothie.js b/smoothie.js
index f47bb6b..90aba29 100644
--- a/smoothie.js
+++ b/smoothie.js
@@ -490,33 +490,33 @@
   SmoothieChart.prototype.updateValueRange = function() {
     // Calculate the current scale of the chart, from all time series.
     var chartOptions = this.options,
-        chartMaxValue = Number.NaN,
-        chartMinValue = Number.NaN;
-
-    for (var d = 0; d < this.seriesSet.length; d++) {
-      // TODO(ndunn): We could calculate / track these values as they stream in.
-      var timeSeries = this.seriesSet[d].timeSeries;
-      if (!isNaN(timeSeries.maxValue)) {
-        chartMaxValue = !isNaN(chartMaxValue) ? Math.max(chartMaxValue, timeSeries.maxValue) : timeSeries.maxValue;
-      }
+        chartMaxValue = chartOptions.maxValue,
+        chartMinValue = chartOptions.minValue;
+
+    if (isNaN(chartMinValue + chartMaxValue)) {
+      for (var d = 0; d < this.seriesSet.length; d++) {
+        // TODO(ndunn): We could calculate / track these values as they stream in.
+        var timeSeries = this.seriesSet[d].timeSeries;
+        if (!isNaN(timeSeries.maxValue)) {
+          chartMaxValue = chartMaxValue > timeSeries.maxValue ? chartMaxValue : timeSeries.maxValue;
+        }
 
-      if (!isNaN(timeSeries.minValue)) {
-        chartMinValue = !isNaN(chartMinValue) ? Math.min(chartMinValue, timeSeries.minValue) : timeSeries.minValue;
+        if (!isNaN(timeSeries.minValue)) {
+          chartMinValue = chartMinValue > timeSeries.minValue ? chartMinValue : timeSeries.minValue;
+        }
       }
     }
 
+    var range = chartMaxValue - chartMinValue;
+
     // Scale the chartMaxValue to add padding at the top if required
-    if (chartOptions.maxValue != null) {
-      chartMaxValue = chartOptions.maxValue;
-    } else {
-      chartMaxValue *= chartOptions.maxValueScale;
+    if (chartOptions.maxValue == null) {
+      chartMaxValue += range * chartOptions.maxValueScale - range;
     }
 
     // Set the minimum if we've specified one
-    if (chartOptions.minValue != null) {
-      chartMinValue = chartOptions.minValue;
-    } else {
-      chartMinValue -= Math.abs(chartMinValue * chartOptions.minValueScale - chartMinValue);
+    if (chartOptions.minValue == null) {
+      chartMinValue -= range * chartOptions.minValueScale - range;
     }
 
     // If a custom range function is set, call it
@@ -527,8 +527,7 @@
     }
 
     if (!isNaN(chartMaxValue) && !isNaN(chartMinValue)) {
-      var targetValueRange = chartMaxValue - chartMinValue;
-      var valueRangeDiff = (targetValueRange - this.currentValueRange);
+      var valueRangeDiff = (chartMaxValue - chartMinValue) - this.currentValueRange;
       var minValueDiff = (chartMinValue - this.currentVisMinValue);
       this.isAnimatingScale = Math.abs(valueRangeDiff) > 0.1 || Math.abs(minValueDiff) > 0.1;
       this.currentValueRange += chartOptions.scaleSmoothing * valueRangeDiff;

From b9279106b09eb5faea2729f7d519b2ef0a419fc7 Mon Sep 17 00:00:00 2001
From: Graeme <megawac@gmail.com>
Date: Tue, 25 Nov 2014 19:36:51 -0500
Subject: [PATCH 2/2] Force [min|max]Value to chartOptions value if provided

---
 smoothie.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/smoothie.js b/smoothie.js
index 90aba29..eb1947b 100644
--- a/smoothie.js
+++ b/smoothie.js
@@ -497,11 +497,11 @@
       for (var d = 0; d < this.seriesSet.length; d++) {
         // TODO(ndunn): We could calculate / track these values as they stream in.
         var timeSeries = this.seriesSet[d].timeSeries;
-        if (!isNaN(timeSeries.maxValue)) {
+        if (chartOptions.maxValue == null && !isNaN(timeSeries.maxValue)) {
           chartMaxValue = chartMaxValue > timeSeries.maxValue ? chartMaxValue : timeSeries.maxValue;
         }
 
-        if (!isNaN(timeSeries.minValue)) {
+        if (chartOptions.minValue == null && !isNaN(timeSeries.minValue)) {
           chartMinValue = chartMinValue > timeSeries.minValue ? chartMinValue : timeSeries.minValue;
         }
       }