Improvements to startAtZero logic (Fixes issue #300)

ChartsOrg · Aug 19, 2015 · 45daf28 · 45daf28
1 parent 2068a5c
commit 45daf28
Show file tree

Hide file tree

Showing 2 changed files with 65 additions and 21 deletions.
diff --git a/Charts/Classes/Charts/BarLineChartViewBase.swift b/Charts/Classes/Charts/BarLineChartViewBase.swift
@@ -319,38 +319,61 @@ public class BarLineChartViewBase: ChartViewBase, UIGestureRecognizerDelegate
         _chartXMax = Double(_data.xVals.count - 1)
         _deltaX = CGFloat(abs(_chartXMax - _chartXMin))
 
-        _leftAxis.axisMaximum = !isnan(_leftAxis.customAxisMax) ? _leftAxis.customAxisMax : (maxLeft + topSpaceLeft)
-        _rightAxis.axisMaximum = !isnan(_rightAxis.customAxisMax) ? _rightAxis.customAxisMax : (maxRight + topSpaceRight)
-        _leftAxis.axisMinimum = !isnan(_leftAxis.customAxisMin) ? _leftAxis.customAxisMin : (minLeft - bottomSpaceLeft)
-        _rightAxis.axisMinimum = !isnan(_rightAxis.customAxisMin) ? _rightAxis.customAxisMin : (minRight - bottomSpaceRight)
+        // Consider sticking one of the edges of the axis to zero (0.0)
 
-        // consider starting at zero (0)
-        if (_leftAxis.isStartAtZeroEnabled)
+        if _leftAxis.isStartAtZeroEnabled
         {
-            if _leftAxis.axisMinimum < 0.0 && _leftAxis.axisMaximum < 0.0
+            if minLeft < 0.0 && maxLeft < 0.0
             {
                 // If the values are all negative, let's stay in the negative zone
+                _leftAxis.axisMinimum = min(0.0, !isnan(_leftAxis.customAxisMin) ? _leftAxis.customAxisMin : (minLeft - bottomSpaceLeft))
                 _leftAxis.axisMaximum = 0.0
             }
-            else if _leftAxis.axisMinimum >= 0.0
+            else if minLeft >= 0.0
             {
                 // We have positive values only, stay in the positive zone
                 _leftAxis.axisMinimum = 0.0
+                _leftAxis.axisMaximum = max(0.0, !isnan(_leftAxis.customAxisMax) ? _leftAxis.customAxisMax : (maxLeft + topSpaceLeft))
             }
+            else
+            {
+                // Stick the minimum to 0.0 or less, and maximum to 0.0 or more (startAtZero for negative/positive at the same time)
+                _leftAxis.axisMinimum = min(0.0, !isnan(_leftAxis.customAxisMin) ? _leftAxis.customAxisMin : (minLeft - bottomSpaceLeft))
+                _leftAxis.axisMaximum = max(0.0, !isnan(_leftAxis.customAxisMax) ? _leftAxis.customAxisMax : (maxLeft + topSpaceLeft))
+            }
+        }
+        else
+        {
+            // Use the values as they are
+            _leftAxis.axisMinimum = !isnan(_leftAxis.customAxisMin) ? _leftAxis.customAxisMin : (minLeft - bottomSpaceLeft)
+            _leftAxis.axisMaximum = !isnan(_leftAxis.customAxisMax) ? _leftAxis.customAxisMax : (maxLeft + topSpaceLeft)
         }
 
-        if (_rightAxis.isStartAtZeroEnabled)
+        if _rightAxis.isStartAtZeroEnabled
         {
-            if _rightAxis.axisMinimum < 0.0 && _rightAxis.axisMaximum < 0.0
+            if minRight < 0.0 && maxRight < 0.0
             {
                 // If the values are all negative, let's stay in the negative zone
+                _rightAxis.axisMinimum = min(0.0, !isnan(_rightAxis.customAxisMin) ? _rightAxis.customAxisMin : (minRight - bottomSpaceRight))
                 _rightAxis.axisMaximum = 0.0
             }
-            else if _rightAxis.axisMinimum >= 0.0
+            else if minRight >= 0.0
             {
                 // We have positive values only, stay in the positive zone
                 _rightAxis.axisMinimum = 0.0
+                _rightAxis.axisMaximum = max(0.0, !isnan(_rightAxis.customAxisMax) ? _rightAxis.customAxisMax : (maxRight + topSpaceRight))
             }
+            else
+            {
+                // Stick the minimum to 0.0 or less, and maximum to 0.0 or more (startAtZero for negative/positive at the same time)
+                _rightAxis.axisMinimum = min(0.0, !isnan(_rightAxis.customAxisMin) ? _rightAxis.customAxisMin : (minRight - bottomSpaceRight))
+                _rightAxis.axisMaximum = max(0.0, !isnan(_rightAxis.customAxisMax) ? _rightAxis.customAxisMax : (maxRight + topSpaceRight))
+            }
+        }
+        else
+        {
+            _rightAxis.axisMinimum = !isnan(_rightAxis.customAxisMin) ? _rightAxis.customAxisMin : (minRight - bottomSpaceRight)
+            _rightAxis.axisMaximum = !isnan(_rightAxis.customAxisMax) ? _rightAxis.customAxisMax : (maxRight + topSpaceRight)
         }
 
         _leftAxis.axisRange = abs(_leftAxis.axisMaximum - _leftAxis.axisMinimum)

diff --git a/Charts/Classes/Charts/RadarChartView.swift b/Charts/Classes/Charts/RadarChartView.swift
@@ -82,21 +82,42 @@ public class RadarChartView: PieRadarChartViewBase
 
         var leftRange = CGFloat(abs(maxLeft - (_yAxis.isStartAtZeroEnabled ? 0.0 : minLeft)))
 
-        var topSpaceLeft = leftRange * _yAxis.spaceTop
-        var bottomSpaceLeft = leftRange * _yAxis.spaceBottom
+        var topSpaceLeft = Double(leftRange * _yAxis.spaceTop)
+        var bottomSpaceLeft = Double(leftRange * _yAxis.spaceBottom)
 
-        _chartXMax = Double(_data.xVals.count) - 1.0
-        _deltaX = CGFloat(abs(_chartXMax - _chartXMin))
+        // Consider sticking one of the edges of the axis to zero (0.0)
 
-        _yAxis.axisMaximum = !isnan(_yAxis.customAxisMax) ? _yAxis.customAxisMax : maxLeft + Double(topSpaceLeft)
-        _yAxis.axisMinimum = !isnan(_yAxis.customAxisMin) ? _yAxis.customAxisMin : minLeft - Double(bottomSpaceLeft)
-
-        // consider starting at zero (0)
-        if (_yAxis.isStartAtZeroEnabled)
+        if _yAxis.isStartAtZeroEnabled
+        {
+            if minLeft < 0.0 && maxLeft < 0.0
+            {
+                // If the values are all negative, let's stay in the negative zone
+                _yAxis.axisMinimum = min(0.0, !isnan(_yAxis.customAxisMin) ? _yAxis.customAxisMin : (minLeft - bottomSpaceLeft))
+                _yAxis.axisMaximum = 0.0
+            }
+            else if minLeft >= 0.0
+            {
+                // We have positive values only, stay in the positive zone
+                _yAxis.axisMinimum = 0.0
+                _yAxis.axisMaximum = max(0.0, !isnan(_yAxis.customAxisMax) ? _yAxis.customAxisMax : (maxLeft + topSpaceLeft))
+            }
+            else
+            {
+                // Stick the minimum to 0.0 or less, and maximum to 0.0 or more (startAtZero for negative/positive at the same time)
+                _yAxis.axisMinimum = min(0.0, !isnan(_yAxis.customAxisMin) ? _yAxis.customAxisMin : (minLeft - bottomSpaceLeft))
+                _yAxis.axisMaximum = max(0.0, !isnan(_yAxis.customAxisMax) ? _yAxis.customAxisMax : (maxLeft + topSpaceLeft))
+            }
+        }
+        else
         {
-            _yAxis.axisMinimum = min(0.0, _yAxis.axisMinimum)
+            // Use the values as they are
+            _yAxis.axisMinimum = !isnan(_yAxis.customAxisMin) ? _yAxis.customAxisMin : (minLeft - bottomSpaceLeft)
+            _yAxis.axisMaximum = !isnan(_yAxis.customAxisMax) ? _yAxis.customAxisMax : (maxLeft + topSpaceLeft)
         }
 
+        _chartXMax = Double(_data.xVals.count) - 1.0
+        _deltaX = CGFloat(abs(_chartXMax - _chartXMin))
+
         _yAxis.axisRange = abs(_yAxis.axisMaximum - _yAxis.axisMinimum)
     }