fixed error-bar error

xchart-demo/src/main/java/com/xeiam/xchart/standalone/ErrorBarTest.java

+/**
+ * Copyright (C) 2013 Xeiam LLC http://xeiam.com
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.xeiam.xchart.standalone;
+
+import java.awt.Color;
+
+import com.xeiam.xchart.Chart;
+import com.xeiam.xchart.Series;
+import com.xeiam.xchart.SeriesColor;
+import com.xeiam.xchart.SeriesLineStyle;
+import com.xeiam.xchart.SeriesMarker;
+import com.xeiam.xchart.SwingWrapper;
+
+/**
+ * @author timmolter
+ */
+public class ErrorBarTest {
+
+  public static void main(String[] args) throws Exception {
+
+    // Test code for plotting
+    double[] xData = new double[] { 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 };
+    double[] yData1 = new double[] { 100, 100, 100, 50, 50, 50, 50 };
+    double[] errdata = new double[] { 50, 20, 10, 50, 40, 20, 10 };
+
+    double[] yData2 = new double[] { 50, 80, 90, 0, 10, 30, 40 };
+    double[] yData3 = new double[] { 150, 120, 110, 100, 90, 70, 60 };
+
+    Chart mychart = new Chart(900, 700);
+    mychart.getStyleManager().setYAxisLogarithmic(false); // set log or linear Y axis
+    mychart.getStyleManager().setYAxisMin(0);
+    mychart.getStyleManager().setYAxisMax(150);
+    mychart.getStyleManager().setErrorBarsColor(Color.black);
+    Series series1 = mychart.addSeries("Error bar test data", xData, yData1, errdata);
+    Series series2 = mychart.addSeries("Y+error", xData, yData2);
+    Series series3 = mychart.addSeries("Y-error", xData, yData3);
+    series1.setLineStyle(SeriesLineStyle.SOLID);
+    series1.setMarker(SeriesMarker.DIAMOND);
+    series1.setMarkerColor(Color.MAGENTA);
+    series2.setLineStyle(SeriesLineStyle.DASH_DASH);
+    series2.setMarker(SeriesMarker.NONE);
+    series2.setLineColor(SeriesColor.RED);
+    series3.setLineStyle(SeriesLineStyle.DASH_DASH);
+    series3.setMarker(SeriesMarker.NONE);
+    series3.setLineColor(SeriesColor.RED);
+
+    new SwingWrapper(mychart).displayChart();
+  }
+
+}

xchart/src/main/java/com/xeiam/xchart/Series.java

@@ -106,7 +106,6 @@ public class Series {
     yMax = yMinMax[1];
     // System.out.println(yMin);
     // System.out.println(yMax);
-
   }
 
   /**

xchart/src/main/java/com/xeiam/xchart/internal/chartpart/PlotContentLineChart.java

@@ -125,9 +125,9 @@ public class PlotContentLineChart extends PlotContent {
         }
 
         // System.out.println(y);
-        double eb = 0.0;
+        BigDecimal eb = BigDecimal.ZERO;
         if (errorBars != null) {
-          eb = ebItr.next().doubleValue();
+          eb = new BigDecimal(ebItr.next().doubleValue());
         }
 
         int xTransform = (int) (xLeftMargin + (x.subtract(xMin).doubleValue() / xMax.subtract(xMin).doubleValue() * xTickSpace));
@@ -179,11 +179,18 @@ public class PlotContentLineChart extends PlotContent {
         if (errorBars != null) {
           g.setColor(getChartPainter().getStyleManager().getErrorBarsColor());
           g.setStroke(errorBarStroke);
-          int bottom = (int) (-1 * bounds.getHeight() * eb / (yMax.subtract(yMin).doubleValue()));
-          int top = (int) (bounds.getHeight() * eb / (yMax.subtract(yMin).doubleValue()));
-          g.drawLine(xOffset, yOffset + bottom, xOffset, yOffset + top);
-          g.drawLine(xOffset - 3, yOffset + bottom, xOffset + 3, yOffset + bottom);
-          g.drawLine(xOffset - 3, yOffset + top, xOffset + 3, yOffset + top);
+
+          BigDecimal topValue = y.add(eb);
+          int topEBTransform = (int) (bounds.getHeight() - (yTopMargin + topValue.subtract(yMin).doubleValue() / yMax.subtract(yMin).doubleValue() * yTickSpace));
+          int topEBOffset = (int) (bounds.getY() + topEBTransform);
+
+          BigDecimal bottomValue = y.subtract(eb);
+          int bottomEBTransform = (int) (bounds.getHeight() - (yTopMargin + bottomValue.subtract(yMin).doubleValue() / yMax.subtract(yMin).doubleValue() * yTickSpace));
+          int bottomEBOffset = (int) (bounds.getY() + bottomEBTransform);
+
+          g.drawLine(xOffset, topEBOffset, xOffset, bottomEBOffset);
+          g.drawLine(xOffset - 3, bottomEBOffset, xOffset + 3, bottomEBOffset);
+          g.drawLine(xOffset - 3, topEBOffset, xOffset + 3, topEBOffset);
         }
       }