fix for issue #826. Reverted behavior added for issue #653. The decis…

…ion was made to anchor min y axis to 0 for bar and stick category charts, but not for other category chart types.

xchart-demo/src/main/java/org/knowm/xchart/standalone/issues/TestForIssue159.java

@@ -41,7 +41,7 @@ public static void main(String[] args) throws Exception {
 
     styler.setAxisTickLabelsColor(Color.darkGray);
     styler.setDatePattern("MM-dd");
-    styler.setYAxisMin(1.0);
+    styler.setYAxisMin(2.0);
     styler.setYAxisMax(10.0);
     styler.setXAxisTickMarkSpacingHint(200);
 

xchart-demo/src/main/java/org/knowm/xchart/standalone/issues/TestForIssue653.java

@@ -24,7 +24,7 @@ public static CategoryChart getCategoryChart() {
     builder.title("Sample Chart").xAxisTitle("X").yAxisTitle("Y").theme(Styler.ChartTheme.Matlab);
     CategoryChart chart = builder.build();
     chart.getStyler().setDefaultSeriesRenderStyle(CategorySeries.CategorySeriesRenderStyle.Line);
-    //        .setYAxisMin(0.0);
+    //            .setYAxisMin(0.0);
 
     chart.addSeries("y(x)", xData, yData);
 

xchart-demo/src/main/java/org/knowm/xchart/standalone/issues/TestForIssue826.java

@@ -0,0 +1,57 @@
+package org.knowm.xchart.standalone.issues;
+
+import java.text.ParseException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import org.knowm.xchart.CategoryChart;
+import org.knowm.xchart.CategoryChartBuilder;
+import org.knowm.xchart.SwingWrapper;
+
+public class TestForIssue826 {
+
+  public static void main(String[] args) throws ParseException {
+
+    CategoryChart chart = getChart();
+    new SwingWrapper(chart).displayChart();
+  }
+
+  public static CategoryChart getChart() {
+    final CategoryChart chart =
+        new CategoryChartBuilder().width(600).height(400).xAxisTitle("X").yAxisTitle("Y").build();
+
+    ArrayList<String> years =
+        new ArrayList<String>(
+            Arrays.asList(
+                new String[] {
+                  "2012", "2013", "2014", "2015", "2016", "2017", "2018", "2019", "2020", "2021",
+                  "2022"
+                }));
+
+    ArrayList<Number> yAData =
+        new ArrayList<Number>(
+            Arrays.asList(
+                new Number[] {
+                  4438887, 4365843, 4050498, 4757380, 4429130, 4692889, 4354087, 4530343, 4572770,
+                  4150489, 4487793
+                }));
+
+    ArrayList<Number> yBData =
+        new ArrayList<Number>(
+            Arrays.asList(
+                new Number[] {
+                  3198714, 3144079, 2859215, 3430605, 3839149, 4042579, 3741823, 3890162, 3731367,
+                  3751216, 4008249
+                }));
+
+    chart.getStyler().setOverlapped(true);
+    chart.getStyler().setYAxisDecimalPattern("###,###.##");
+
+    chart.addSeries("A", years, yAData);
+    chart.addSeries("B", years, yBData);
+
+    //    chart.getStyler().setYAxisMin(2600000.0);
+    chart.setTitle(Double.toString(2600000.0));
+
+    return chart;
+  }
+}

xchart/src/main/java/org/knowm/xchart/internal/chartpart/AxisPair.java

@@ -471,20 +471,21 @@ private void overrideMinMaxForYAxis(Axis yAxis) {
     }
 
     // override min and maxValue if specified
-    if (chart.getStyler().getYAxisMin(yAxis.getYIndex()) != null
-        && !(chart.getStyler() instanceof BoxStyler)) {
-      overrideYAxisMinValue = chart.getStyler().getYAxisMin(yAxis.getYIndex());
-    } else if (chart.getStyler().getYAxisMin() != null
-        && !(chart.getStyler() instanceof BoxStyler)) {
-      overrideYAxisMinValue = chart.getStyler().getYAxisMin();
-    }
 
-    if (chart.getStyler().getYAxisMax(yAxis.getYIndex()) != null
-        && !(chart.getStyler() instanceof BoxStyler)) {
-      overrideYAxisMaxValue = chart.getStyler().getYAxisMax(yAxis.getYIndex());
-    } else if (chart.getStyler().getYAxisMax() != null
-        && !(chart.getStyler() instanceof BoxStyler)) {
-      overrideYAxisMaxValue = chart.getStyler().getYAxisMax();
+    if (!(chart.getStyler() instanceof BoxStyler)) {
+
+      // min
+      if (chart.getStyler().getYAxisMin(yAxis.getYIndex()) != null) {
+        overrideYAxisMinValue = chart.getStyler().getYAxisMin(yAxis.getYIndex());
+      } else if (chart.getStyler().getYAxisMin() != null) {
+        overrideYAxisMinValue = chart.getStyler().getYAxisMin();
+      }
+      // max
+      if (chart.getStyler().getYAxisMax(yAxis.getYIndex()) != null) {
+        overrideYAxisMaxValue = chart.getStyler().getYAxisMax(yAxis.getYIndex());
+      } else if (chart.getStyler().getYAxisMax() != null) {
+        overrideYAxisMaxValue = chart.getStyler().getYAxisMax();
+      }
     }
 
     yAxis.setMin(overrideYAxisMinValue);

xchart/src/main/java/org/knowm/xchart/internal/chartpart/AxisTickCalculator_.java

@@ -60,8 +60,8 @@ public abstract class AxisTickCalculator_ implements AxisTickCalculator {
 
     this.axisDirection = axisDirection;
     this.workingSpace = workingSpace;
-    this.minValue = getAxisMinValue(styler, axisDirection, minValue);
-    this.maxValue = getAxisMaxValue(styler, axisDirection, maxValue);
+    this.minValue = minValue;
+    this.maxValue = maxValue;
     this.styler = styler;
   }
 
@@ -79,8 +79,8 @@ public abstract class AxisTickCalculator_ implements AxisTickCalculator {
     axisValuesWithMinMax.addAll(axisValues);
     axisValuesWithMinMax.add(maxValue);
     this.axisValues = new ArrayList<>(axisValuesWithMinMax);
-    this.minValue = getAxisMinValue(styler, axisDirection, minValue);
-    this.maxValue = getAxisMaxValue(styler, axisDirection, maxValue);
+    this.minValue = minValue;
+    this.maxValue = maxValue;
     this.styler = styler;
   }
 
@@ -192,7 +192,7 @@ protected void calculate() {
     // same value i.e. "#0.00" for 0.0, 0.0001, 0.0002
     // issue #582
     if (isNumberFormatChoppingDecimals(maxValue, minValue)) {
-      System.out.println("returning");
+      //      System.out.println("returning");
       return;
     }
 
@@ -421,48 +421,6 @@ boolean areAllTickLabelsUnique(List<?> tickLabels) {
     return new LinkedHashSet<>(tickLabels).size() == tickLabels.size();
   }
 
-  /**
-   * Determines the axis min value, which may differ from the min value of the respective data (e.g.
-   * for bar charts).
-   *
-   * @param styler the chart {@link Styler}
-   * @param axisDirection the axis {@link Direction}
-   * @param dataMinValue the minimum value of the data corresponding with the axis.
-   * @return the axis min value
-   */
-  private static double getAxisMinValue(
-      Styler styler, Direction axisDirection, double dataMinValue) {
-
-    // special case for category charts
-    if (styler instanceof CategoryStyler) {
-      CategoryStyler categoryStyler = (CategoryStyler) styler;
-      if ((categoryStyler.getDefaultSeriesRenderStyle()
-                  == CategorySeries.CategorySeriesRenderStyle.Bar
-              || categoryStyler.getDefaultSeriesRenderStyle()
-                  == CategorySeries.CategorySeriesRenderStyle.Stick)
-          && dataMinValue > 0) {
-        return 0;
-      }
-    }
-    return dataMinValue;
-  }
-
-  /**
-   * Determines the axis max value, which may differ from the max value of the respective data (e.g.
-   * for bar charts).
-   *
-   * @param styler the chart {@link Styler}
-   * @param axisDirection the axis {@link Direction}
-   * @param dataMaxValue the maximum value of the data corresponding with the axis.
-   * @return the axis max value
-   */
-  private static double getAxisMaxValue(
-      Styler styler, Direction axisDirection, double dataMaxValue) {
-    if (Direction.Y.equals(axisDirection) && styler instanceof CategoryStyler && dataMaxValue < 0)
-      return 0;
-    return dataMaxValue;
-  }
-
   private boolean isNumberFormatChoppingDecimals(double axisMax, double axisMin) {
 
     //        System.out.println("axisMax = " + axisMax);