new plotter

android-app/src/main/java/org/solovyev/android/calculator/CalculatorActivityLauncher.java

@@ -11,7 +11,6 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.TextView;
 import com.actionbarsherlock.app.SherlockFragmentActivity;
-import org.achartengine.ChartFactory;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.AndroidUtils2;
@@ -98,7 +97,6 @@ public final class CalculatorActivityLauncher implements CalculatorEventListener
 
 	public static void plotGraph(@NotNull final Context context){
 		final Intent intent = new Intent();
-		intent.putExtra(ChartFactory.TITLE, context.getString(R.string.c_graph));
 		intent.setClass(context, CalculatorPlotActivity.class);
         AndroidUtils2.addFlags(intent, false, context);
 		context.startActivity(intent);

android-app/src/main/java/org/solovyev/android/calculator/plot/AbstractGraphCalculator.java

@@ -0,0 +1,101 @@
+package org.solovyev.android.calculator.plot;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 1/18/13
+ * Time: 9:03 PM
+ */
+public abstract class AbstractGraphCalculator implements GraphCalculator {
+
+    @NotNull
+    protected final GraphData next = GraphData.newEmptyInstance();
+
+    @NotNull
+    private final GraphData endGraph = GraphData.newEmptyInstance();
+
+    @NotNull
+    private final GraphData startGraph = GraphData.newEmptyInstance();
+
+    @Override
+    public final void computeGraph(@NotNull XyFunction f, float xMin, float xMax, @NotNull GraphData graph, @NotNull GraphsData graphsData, @NotNull Graph2dDimensions dimensions) {
+        if (f.getArity() == 0) {
+            final float v = (float) f.eval();
+            graph.clear();
+            graph.push(xMin, v);
+            graph.push(xMax, v);
+            return;
+        }
+
+        float yMin = graphsData.getLastYMin();
+        float yMax = graphsData.getLastYMin();
+
+        // prepare graph
+        if (!graph.empty()) {
+            if (xMin >= graphsData.getLastXMin()) {
+                // |------[---erased---|------data----|---erased--]------ old data
+                // |-------------------[------data----]------------------ new data
+                //                    xMin           xMax
+                //
+                // OR
+                //
+                // |------[---erased---|------data----]----------- old data
+                // |-------------------[------data----<---->]----- new data
+                //                    xMin                 xMax
+                graph.eraseBefore(xMin);
+                if ( xMax <= graphsData.getLastXMax() ) {
+                    graph.eraseAfter(xMax);
+                    // nothing to compute
+                } else {
+                    xMin = graph.getLastX();
+                    compute(f, xMin, xMax, yMin, yMax, endGraph, dimensions);
+                }
+            } else {
+                // |--------------------[-----data----|---erased----]-- old data
+                // |------[<------------>-----data----]---------------- new data
+                //       xMin                        xMax
+                //
+                // OR
+                //
+                // |--------------------[------data--]----|----------- old data
+                // |-------[<----------->------data--<--->]-----------new data
+                //        xMin                           xMax
+
+                if ( xMax <= graphsData.getLastXMax() ) {
+                    graph.eraseAfter(xMax);
+                    xMax = graph.getFirstX();
+                    compute(f, xMin, xMax, yMin, yMax, startGraph, dimensions);
+                } else {
+                    compute(f, xMin, graph.getFirstX(), yMin, yMax, startGraph, dimensions);
+                    compute(f, graph.getLastX(), xMax, yMin, yMax, endGraph, dimensions);
+                }
+            }
+        } else {
+            compute(f, xMin, xMax, yMin, yMax, graph, dimensions);
+        }
+
+        if (!endGraph.empty()) {
+            // first add ending because it's fast
+            graph.append(endGraph);
+        }
+
+        if (!startGraph.empty()) {
+            startGraph.append(graph);
+            graph.swap(startGraph);
+        }
+
+
+        next.clear();
+        endGraph.clear();
+        startGraph.clear();
+    }
+
+    protected abstract void compute(@NotNull XyFunction f,
+                                    float xMin,
+                                    float xMax,
+                                    float yMin,
+                                    float yMax,
+                                    @NotNull GraphData graph,
+                                    @NotNull Graph2dDimensions dimensions);
+}

android-app/src/main/java/org/solovyev/android/calculator/plot/ArityPlotFunction.java

@@ -1,46 +0,0 @@
-package org.solovyev.android.calculator.plot;
-
-import org.javia.arity.Function;
-import org.jetbrains.annotations.NotNull;
-
-/**
- * User: serso
- * Date: 1/5/13
- * Time: 7:35 PM
- */
-public class ArityPlotFunction {
-
-    @NotNull
-    private Function function;
-
-    @NotNull
-    private PlotLineDef lineDef;
-
-    private ArityPlotFunction() {
-    }
-
-    @NotNull
-    public static ArityPlotFunction newInstance(@NotNull Function function) {
-        return newInstance(function, PlotLineDef.newDefaultInstance());
-    }
-
-    @NotNull
-    public static ArityPlotFunction newInstance(@NotNull Function function, @NotNull PlotLineDef lineDef) {
-        final ArityPlotFunction result = new ArityPlotFunction();
-
-        result.function = function;
-        result.lineDef = lineDef;
-
-        return result;
-    }
-
-    @NotNull
-    public Function getFunction() {
-        return function;
-    }
-
-    @NotNull
-    public PlotLineDef getLineDef() {
-        return lineDef;
-    }
-}

android-app/src/main/java/org/solovyev/android/calculator/plot/CalculatorGraph2dView.java

@@ -12,7 +12,6 @@ import org.jetbrains.annotations.NotNull;
 import org.solovyev.common.math.Point2d;
 
 import java.text.DecimalFormat;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
@@ -46,10 +45,6 @@ public class CalculatorGraph2dView extends View implements GraphView {
     **********************************************************************
     */
 
-    // view width and height in pixels
-    private int widthPxs;
-    private int heightPxs;
-
 	@NotNull
     private final Matrix matrix = new Matrix();
 
@@ -66,25 +61,8 @@ public class CalculatorGraph2dView extends View implements GraphView {
 
     @NotNull
     private GraphViewHelper graphViewHelper = GraphViewHelper.newDefaultInstance();
-
-    private final GraphData next = GraphData.newEmptyInstance();
-
-    private final GraphData endGraph = GraphData.newEmptyInstance();
-
     @NotNull
-    private List<GraphData> graphs = new ArrayList<GraphData>(graphViewHelper.getFunctionPlotDefs().size());
+    private final GraphsData graphsData = new GraphsData(this);
-
-    // current position of camera in graph coordinates
-    private float x0;
-    private float y0;
-
-    // graph width in function units (NOT screen pixels)
-    private float gWidth = 20;
-
-    private float lastXMin;
-
-    private float lastYMin;
-    private float lastYMax;
 
     private float lastTouchXPxs = NO_TOUCH;
 	private float lastTouchYPxs = NO_TOUCH;
@@ -101,6 +79,21 @@ public class CalculatorGraph2dView extends View implements GraphView {
     @NotNull
     private Scroller scroller;
 
+    @NotNull
+    private final Graph2dDimensions dimensions = new Graph2dDimensions(this);
+
+    private final GraphCalculator graphCalculator = new GraphCalculatorImpl();
+
+    private boolean mDrawn = false;
+
+    /*
+    **********************************************************************
+    *
+    *                           CONSTRUCTORS
+    *
+    **********************************************************************
+    */
+
     public CalculatorGraph2dView(Context context, AttributeSet attrs) {
         super(context, attrs);
         init(context);
@@ -119,39 +112,21 @@ public class CalculatorGraph2dView extends View implements GraphView {
         paint.setAntiAlias(false);
         textPaint.setAntiAlias(true);
 
-        widthPxs = this.getWidth();
+        dimensions.setViewDimensions(this);
-        heightPxs = this.getHeight();
-    }
-
-    @NotNull
-    public Bitmap captureScreenshot() {
-        final Bitmap result = Bitmap.createBitmap(widthPxs, heightPxs, Bitmap.Config.RGB_565);
-        Canvas canvas = new Canvas(result);
-        onDraw(canvas);
-        return result;
     }
 
     @Override
-    public void setXRange(float xMin, float xMax) {
+    public void init(@NotNull PlotViewDef plotViewDef) {
-        this.gWidth = xMax - xMin;
+        this.graphViewHelper = GraphViewHelper.newInstance(plotViewDef, Collections.<PlotFunction>emptyList());
-        this.x0 = xMin + gWidth / 2;
-        this.y0 = 0;
     }
 
-    private void clearAllGraphs() {
+    /*
-        for (GraphData graph : graphs) {
+    **********************************************************************
-            graph.clear();
+    *
-        }
+    *                           METHODS
-
+    *
-        while (graphViewHelper.getFunctionPlotDefs().size() > graphs.size()) {
+    **********************************************************************
-            graphs.add(GraphData.newEmptyInstance());
+    */
-        }
-    }
-
-    @Override
-    public void init(@NotNull FunctionViewDef functionViewDef) {
-        this.graphViewHelper = GraphViewHelper.newInstance(functionViewDef, Collections.<PlotFunction>emptyList());
-    }
 
     public void setPlotFunctions(@NotNull List<PlotFunction> plotFunctions) {
 
@@ -163,8 +138,31 @@ public class CalculatorGraph2dView extends View implements GraphView {
         }
 
         this.graphViewHelper = this.graphViewHelper.copy(plotFunctions);
-        clearAllGraphs();
+        invalidateGraphs();
-        invalidate();
+    }
+
+    @NotNull
+    @Override
+    public List<PlotFunction> getPlotFunctions() {
+        return this.graphViewHelper.getPlotFunctions();
+    }
+
+    @NotNull
+    public Bitmap captureScreenshot() {
+        final Bitmap result = Bitmap.createBitmap(dimensions.getVWidthPxs(), dimensions.getVHeightPxs(), Bitmap.Config.RGB_565);
+        onDraw(new Canvas(result));
+        return result;
+    }
+
+    @Override
+    public void invalidateGraphs() {
+        if (mDrawn) {
+            mDrawn = false;
+
+            graphsData.clear();
+
+            invalidate();
+        }
     }
 
     public void onResume() {
@@ -179,149 +177,22 @@ public class CalculatorGraph2dView extends View implements GraphView {
     }
 
     protected void onSizeChanged(int w, int h, int ow, int oh) {
-        widthPxs = w;
+        dimensions.setViewDimensions(w, h);
-        heightPxs = h;
-        clearAllGraphs();
     }
 
-    protected void onDraw(Canvas canvas) {
+    protected void onDraw(@NotNull Canvas canvas) {
-        if (graphViewHelper.getFunctionPlotDefs().size() == 0) {
+        if (!graphViewHelper.getPlotFunctions().isEmpty()) {
-            return;
-        }
-        if (scroller.computeScrollOffset()) {
-            final float ratio = getRatio();
-            x0 = scroller.getCurrX() * ratio;
-            y0 = scroller.getCurrY() * ratio;
-            if (!scroller.isFinished()) {
-                invalidate();
-            }
-        }
-        drawGraph(canvas);
-    }
 
-    // distance from (x,y) to the line (x1,y1) to (x2,y2), squared, multiplied by 4
+            if (scroller.computeScrollOffset()) {
-    /*
+                final float ratio = dimensions.getGraphToViewRatio();
-    private float distance(float x1, float y1, float x2, float y2, float x, float y) {
+                dimensions.setXY(scroller.getCurrX() * ratio, scroller.getCurrY() * ratio);
-        float dx = x2 - x1;
+                if (!scroller.isFinished()) {
-        float dy = y2 - y1;
+                    invalidate();
-        float mx = x - x1;
-        float my = y - y1;
-        float up = dx*my - dy*mx;
-        return up*up*4/(dx*dx + dy*dy);
-    }
-    */
-
-    // distance as above when x==(x1+x2)/2. 
-    private float distance2(float x1, float y1, float x2, float y2, float y) {
-        final float dx = x2 - x1;
-        final float dy = y2 - y1;
-        final float up = dx * (y1 + y2 - y - y);
-        return up * up / (dx * dx + dy * dy);
-    }
-
-    private void computeGraph(@NotNull XyFunction f,
-                              float xMin,
-                              float xMax,
-                              float yMin,
-                              float yMax,
-                              @NotNull GraphData graph) {
-        if (f.getArity() == 0) {
-            final float v = (float) f.eval();
-            graph.clear();
-            graph.push(xMin, v);
-            graph.push(xMax, v);
-            return;
-        }
-
-        // prepare graph
-        if (!graph.empty()) {
-            if (xMin >= lastXMin) {
-                graph.eraseBefore(xMin);
-            } else {
-                graph.eraseAfter(xMax);
-                xMax = Math.min(xMax, graph.firstX());
-                graph.swap(endGraph);
-            }
-        }
-        if (graph.empty()) {
-            graph.push(xMin, (float)f.eval(xMin));
-        }
-
-        final float ratio = getRatio();
-        final float maxStep = 15.8976f * ratio;
-        final float minStep = .05f * ratio;
-        float ythresh = ratio;
-        ythresh = ythresh * ythresh;
-
-
-        float leftX, leftY;
-        float rightX = graph.topX(), rightY = graph.topY();
-        int nEval = 1;
-        while (true) {
-            leftX = rightX;
-            leftY = rightY;
-            if (leftX > xMax) {
-                break;
-            }
-            if (next.empty()) {
-                float x = leftX + maxStep;
-                next.push(x, (float) f.eval(x));
-                ++nEval;
-            }
-            rightX = next.topX();
-            rightY = next.topY();
-            next.pop();
-
-            if (leftY != leftY && rightY != rightY) { // NaN
-                continue;
-            }
-
-            float dx = rightX - leftX;
-            float middleX = (leftX + rightX) / 2;
-            float middleY = (float) f.eval(middleX);
-            ++nEval;
-            boolean middleIsOutside = (middleY < leftY && middleY < rightY) || (leftY < middleY && rightY < middleY);
-            if (dx < minStep) {
-                // Calculator.log("minStep");
-                if (middleIsOutside) {
-                    graph.push(rightX, Float.NaN);
-                }
-                graph.push(rightX, rightY);
-                continue;
-            }
-            if (middleIsOutside && ((leftY < yMin && rightY > yMax) || (leftY > yMax && rightY < yMin))) {
-                graph.push(rightX, Float.NaN);
-                graph.push(rightX, rightY);
-                // Calculator.log("+-inf");
-                continue;
-            }
-
-            if (!middleIsOutside) {
-                /*
-                float diff = leftY + rightY - middleY - middleY;
-                float dy = rightY - leftY;
-                float dx2 = dx*dx;
-                float distance = dx2*diff*diff/(dx2+dy*dy);
-                */
-                // Calculator.log("" + dx + ' ' + leftY + ' ' + middleY + ' ' + rightY + ' ' + distance + ' ' + ythresh);
-                if (distance2(leftX, leftY, rightX, rightY, middleY) < ythresh) {
-                    graph.push(rightX, rightY);
-                    continue;
                 }
             }
-            next.push(rightX, rightY);
-            next.push(middleX, middleY);
-            rightX = leftX;
-            rightY = leftY;
-        }
-        if (!endGraph.empty()) {
-            graph.append(endGraph);
-        }
-        long t2 = System.currentTimeMillis();
-        // Calculator.log("graph points " + graph.size + " evals " + nEval + " time " + (t2-t1));
 
-        next.clear();
+            drawGraph(canvas);
-        endGraph.clear();
+        }
     }
 
     private static void graphToPath(@NotNull GraphData graph, @NotNull Path path) {
@@ -352,51 +223,30 @@ public class CalculatorGraph2dView extends View implements GraphView {
         }
     }
 
-    private static float getStep(float width) {
-        float f = 1;
-        while (width / f > TICKS_COUNT) {
-            f *= 10;
-        }
-        
-        while (width / f < TICKS_COUNT / 10) {
-            f /= 10;
-        }
-
-        final float r = width / f;
-        if (r < TICKS_COUNT / 5) {
-            return f / 5;
-        } else if (r < TICKS_COUNT / 2) {
-            return f / 2;
-        } else {
-            return f;
-        }
-    }
-
     private void drawGraph(@NotNull Canvas canvas) {
-        final float graphHeight = getGraphHeight();
+        mDrawn = true;
 
-        final float xMin = getXMin();
+        final float graphHeight = dimensions.getGraphHeight();
-        final float xMax = getXMax(xMin);
 
-        final float yMin = getYMin(graphHeight);
+        final float xMin = dimensions.getXMin();
-        final float yMax = getYMax(graphHeight, yMin);
+        final float xMax = dimensions.getXMax(xMin);
 
-        if (yMin < lastYMin || yMax > lastYMax) {
+        final float yMin = dimensions.getYMin(graphHeight);
-            float halfGraphHeight = graphHeight / 2;
+        final float yMax = dimensions.getYMax(graphHeight, yMin);
-            lastYMin = yMin - halfGraphHeight;
+        final float widthPxs = dimensions.getVWidthPxs();
-            lastYMax = yMax + halfGraphHeight;
+        final float heightPxs = dimensions.getVHeightPxs();
-            clearAllGraphs();
+
-        }
+        graphsData.checkBoundaries(graphHeight, yMin, yMax);
 
         // set background
-        canvas.drawColor(graphViewHelper.getFunctionViewDef().getBackgroundColor());
+        canvas.drawColor(graphViewHelper.getPlotViewDef().getBackgroundColor());
 
         // prepare paint
         paint.setStrokeWidth(0);
         paint.setAntiAlias(false);
         paint.setStyle(Paint.Style.STROKE);
 
-        final float ratio = getRatio();
+        final float ratio = dimensions.getGraphToViewRatio();
 
         float x0px = -xMin / ratio;
         if (x0px < 25) {
@@ -413,16 +263,16 @@ public class CalculatorGraph2dView extends View implements GraphView {
         }
 
 
-		final float tickStep = getStep(gWidth);
+		final float tickStep = getTickStep(dimensions.getGWidth());
 		final int tickDigits = countTickDigits(tickStep);
 
         {
             // GRID
 
             paint.setPathEffect(new DashPathEffect(new float[]{5, 10}, 0));
-            paint.setColor(graphViewHelper.getFunctionViewDef().getGridColor());
+            paint.setColor(graphViewHelper.getPlotViewDef().getGridColor());
 
-            textPaint.setColor(graphViewHelper.getFunctionViewDef().getAxisLabelsColor());
+            textPaint.setColor(graphViewHelper.getPlotViewDef().getAxisLabelsColor());
             textPaint.setTextSize(12);
             textPaint.setTextAlign(Paint.Align.CENTER);
 
@@ -461,7 +311,7 @@ public class CalculatorGraph2dView extends View implements GraphView {
         {
             // AXIS
 
-            paint.setColor(graphViewHelper.getFunctionViewDef().getAxisColor());
+            paint.setColor(graphViewHelper.getPlotViewDef().getAxisColor());
             canvas.drawLine(x0px, 0, x0px, heightPxs, paint);
             canvas.drawLine(0, y0px, widthPxs, y0px, paint);
         }
@@ -471,13 +321,13 @@ public class CalculatorGraph2dView extends View implements GraphView {
 
 			if (lastTouchXPxs != NO_TOUCH && lastTouchYPxs != NO_TOUCH) {
 
-				paint.setColor(graphViewHelper.getFunctionViewDef().getGridColor());
+				paint.setColor(graphViewHelper.getPlotViewDef().getGridColor());
 				paint.setAlpha(100);
 
 				canvas.drawLine(lastTouchXPxs, 0, lastTouchXPxs, heightPxs, paint);
 				canvas.drawLine(0, lastTouchYPxs, widthPxs, lastTouchYPxs, paint);
 
-				final Point2d lastTouch = toGraphCoordinates(lastTouchXPxs, lastTouchYPxs);
+				final Point2d lastTouch = dimensions.toGraphCoordinates(lastTouchXPxs, lastTouchYPxs);
 				final String touchLabel = "[" + formatTick(lastTouch.getX(), tickDigits + 1) + ", " + formatTick(lastTouch.getY(), tickDigits + 1) + "]";
 				canvas.drawText(touchLabel, 0, touchLabel.length(), lastTouchXPxs - 40, lastTouchYPxs - 40, textPaint);
 
@@ -488,7 +338,7 @@ public class CalculatorGraph2dView extends View implements GraphView {
 
 
         matrix.reset();
-        matrix.preTranslate(-this.x0, -this.y0);
+        matrix.preTranslate(-dimensions.getX0(), -dimensions.getY0());
         matrix.postScale(1/ratio, -1/ratio);
         matrix.postTranslate(widthPxs / 2, heightPxs / 2);
 
@@ -497,16 +347,17 @@ public class CalculatorGraph2dView extends View implements GraphView {
         {
             //GRAPH
 
-            final List<PlotFunction> functionPlotDefs = graphViewHelper.getFunctionPlotDefs();
+            final List<PlotFunction> functionPlotDefs = graphViewHelper.getPlotFunctions();
 
             // create path once
             final Path path = new Path();
 
             for (int i = 0; i < functionPlotDefs.size(); i++) {
                 final PlotFunction fpd = functionPlotDefs.get(i);
-                computeGraph(fpd.getXyFunction(), xMin, xMax, lastYMin, lastYMax, graphs.get(i));
 
-                graphToPath(graphs.get(i), path);
+                graphCalculator.computeGraph(fpd.getXyFunction(), xMin, xMax, graphsData.get(i), graphsData, dimensions);
+
+                graphToPath(graphsData.get(i), path);
 
                 path.transform(matrix);
 
@@ -517,13 +368,14 @@ public class CalculatorGraph2dView extends View implements GraphView {
         }
 
 
-        lastXMin = xMin;
+        graphsData.setLastXMin(xMin);
+        graphsData.setLastXMax(xMax);
     }
 
     /*
     **********************************************************************
     *
-    *                           TICK FORMAT
+    *                           TICKS
     *
     **********************************************************************
     */
@@ -557,6 +409,27 @@ public class CalculatorGraph2dView extends View implements GraphView {
         }
     }
 
+
+    private static float getTickStep(float width) {
+        float f = 1;
+        while (width / f > TICKS_COUNT) {
+            f *= 10;
+        }
+
+        while (width / f < TICKS_COUNT / 10) {
+            f /= 10;
+        }
+
+        final float r = width / f;
+        if (r < TICKS_COUNT / 5) {
+            return f / 5;
+        } else if (r < TICKS_COUNT / 2) {
+            return f / 2;
+        } else {
+            return f;
+        }
+    }
+
     /*
     **********************************************************************
     *
@@ -565,64 +438,32 @@ public class CalculatorGraph2dView extends View implements GraphView {
     **********************************************************************
     */
 
-	private Point2d toGraphCoordinates(float xPxs, float yPxs) {
-		return new Point2d(xPxs * getRatio() + getXMin(), - (yPxs * getRatio() + getYMin()));
-	}
-
     // X
 
     public float getXMin() {
-        return x0 - gWidth / 2;
+        return dimensions.getXMin();
-    }
-
-    private float getXMax(float minX) {
-        return minX + gWidth;
     }
 
     public float getXMax() {
-        return getXMax(getXMin());
+        return dimensions.getXMax();
     }
 
     // Y
 
     @Override
     public float getYMin() {
-        return getYMin(getGraphHeight());
+        return dimensions.getYMin();
     }
 
 
-    public float getYMin(float graphHeight) {
-        return y0 - graphHeight / 2;
-    }
-
     @Override
     public float getYMax() {
-        final float graphHeight = getGraphHeight();
+        return dimensions.getYMax();
-        return getYMax(graphHeight, getYMin(graphHeight));
     }
 
-    public float getYMax(float graphHeight, float yMin) {
+    @Override
-        return yMin + graphHeight;
+    public void setXRange(float xMin, float xMax) {
-    }
+        this.dimensions.setXRange(xMin, xMax);
-
-    private float getGraphHeight() {
-        return gWidth * getAspectRatio();
-    }
-
-    private float getRatio() {
-        if (widthPxs != 0) {
-            return gWidth / widthPxs;
-        } else {
-            return 0;
-        }
-    }
-
-    private float getAspectRatio() {
-        if (widthPxs != 0) {
-            return ((float)heightPxs) / widthPxs;
-        } else {
-            return 0;
-        }
     }
 
     /*
@@ -647,13 +488,11 @@ public class CalculatorGraph2dView extends View implements GraphView {
     public void onZoom(boolean zoomIn) {
         if (zoomIn) {
             if (canZoomIn()) {
-                gWidth /= 2;
+                dimensions.setGWidth(dimensions.getGWidth() / 2);
-                invalidateGraphs();
             }
         } else {
             if (canZoomOut()) {
-                gWidth *= 2;
+                dimensions.setGWidth(dimensions.getGWidth() * 2);
-                invalidateGraphs();
             }
         }
         zoomController.setZoomInEnabled(canZoomIn());
@@ -700,7 +539,7 @@ public class CalculatorGraph2dView extends View implements GraphView {
     }
 
     public void onTouchUp(float x, float y) {
-        final float ratio = getRatio();
+        final float ratio = dimensions.getGraphToViewRatio();
 
 		lastTouchXPxs = NO_TOUCH;
 		lastTouchYPxs = NO_TOUCH;
@@ -715,35 +554,26 @@ public class CalculatorGraph2dView extends View implements GraphView {
         } else if (asy < asx / 3) {
             sy = 0;
         }
-        scroller.fling(Math.round(x0 / ratio), Math.round(y0 / ratio), Math.round(sx), Math.round(sy), Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MIN_VALUE, Integer.MAX_VALUE);
+        scroller.fling(Math.round(dimensions.getX0() / ratio), Math.round(dimensions.getY0() / ratio), Math.round(sx), Math.round(sy), Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MIN_VALUE, Integer.MAX_VALUE);
         invalidate();
     }
 
     public void onTouchZoomDown(float x1, float y1, float x2, float y2) {
-        zoomTracker.start(gWidth, x1, y1, x2, y2);
+        zoomTracker.start(dimensions.getGWidth(), x1, y1, x2, y2);
     }
 
     public void onTouchZoomMove(float x1, float y1, float x2, float y2) {
         if (!zoomTracker.update(x1, y1, x2, y2)) {
             return;
         }
-        float targetGwidth = zoomTracker.value;
+        float targetGWidth = zoomTracker.value;
-        if (targetGwidth > .25f && targetGwidth < 200) {
+        if (targetGWidth > .25f && targetGWidth < 200) {
-            gWidth = targetGwidth;
+            dimensions.setGWidth(targetGWidth);
         }
-        // scroll(-zoomTracker.moveX, zoomTracker.moveY);
-        invalidateGraphs();
-        // Calculator.log("zoom redraw");
-    }
-
-    private void invalidateGraphs() {
-        clearAllGraphs();
-        lastYMin = lastYMax = 0;
-        invalidate();
     }
 
     private void scroll(float deltaX, float deltaY) {
-        final float scale = gWidth / widthPxs;
+        final float scale = dimensions.getGWidth() / dimensions.getVWidthPxs();
         float dx = deltaX * scale;
         float dy = deltaY * scale;
         final float adx = Math.abs(dx);
@@ -753,7 +583,7 @@ public class CalculatorGraph2dView extends View implements GraphView {
         } else if (ady < adx / 3) {
             dy = 0;
         }
-        x0 += dx;
+
-        y0 += dy;
+        dimensions.increaseXY(dx, dy);
     }
 }

android-app/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotFragment.java

@@ -44,7 +44,7 @@ public class CalculatorPlotFragment extends AbstractCalculatorPlotFragment {
             graphView = new CalculatorGraph2dView(getActivity());
         }
 
-        graphView.init(FunctionViewDef.newInstance(Color.WHITE, Color.WHITE, Color.DKGRAY, getBgColor()));
+        graphView.init(PlotViewDef.newInstance(Color.WHITE, Color.WHITE, Color.DKGRAY, getBgColor()));
         //graphView.setXRange((float)plotBoundaries.getXMin(), (float)plotBoundaries.getXMax());
         graphView.setPlotFunctions(plotData.getFunctions());
 
@@ -99,12 +99,4 @@ public class CalculatorPlotFragment extends AbstractCalculatorPlotFragment {
         }
     }
 
-    /*
-    **********************************************************************
-    *
-    *                           STATIC
-    *
-    **********************************************************************
-    */
-
 }

android-app/src/main/java/org/solovyev/android/calculator/plot/Graph2dDimensions.java

@@ -0,0 +1,165 @@
+package org.solovyev.android.calculator.plot;
+
+import android.view.View;
+import org.jetbrains.annotations.NotNull;
+import org.solovyev.common.math.Point2d;
+
+/**
+ * User: serso
+ * Date: 1/18/13
+ * Time: 7:59 PM
+ */
+public class Graph2dDimensions {
+
+    @NotNull
+    private GraphView graphView;
+
+    // view width and height in pixels
+    private int vWidthPxs;
+    private int vHeightPxs;
+
+    // current position of camera in graph coordinates
+    private float x0;
+    private float y0;
+
+    // graph width in function units (NOT screen pixels)
+    private float gWidth = 20;
+
+    public Graph2dDimensions(@NotNull GraphView graphView) {
+        this.graphView = graphView;
+    }
+
+    /*
+    **********************************************************************
+    *
+    *                           METHODS
+    *
+    **********************************************************************
+    */
+
+    @NotNull
+    Point2d toGraphCoordinates(float xPxs, float yPxs) {
+        return new Point2d(xPxs * getGraphToViewRatio() + getXMin(), - (yPxs * getGraphToViewRatio() + getYMin()));
+    }
+
+    // X
+
+    public float getXMin() {
+        return x0 - gWidth / 2;
+    }
+
+    float getXMax(float minX) {
+        return minX + gWidth;
+    }
+
+    public float getXMax() {
+        return getXMax(getXMin());
+    }
+
+    // Y
+
+    public float getYMin() {
+        return getYMin(getGraphHeight());
+    }
+
+
+    public float getYMin(float graphHeight) {
+        return y0 - graphHeight / 2;
+    }
+
+    public float getYMax() {
+        final float graphHeight = getGraphHeight();
+        return getYMax(graphHeight, getYMin(graphHeight));
+    }
+
+    public float getYMax(float graphHeight, float yMin) {
+        return yMin + graphHeight;
+    }
+
+    float getGraphHeight() {
+        return gWidth * getAspectRatio();
+    }
+
+    float getGraphToViewRatio() {
+        if (vWidthPxs != 0) {
+            return gWidth / vWidthPxs;
+        } else {
+            return 0;
+        }
+    }
+
+    private float getAspectRatio() {
+        if (vWidthPxs != 0) {
+            return ((float) vHeightPxs) / vWidthPxs;
+        } else {
+            return 0;
+        }
+    }
+
+    public int getVWidthPxs() {
+        return vWidthPxs;
+    }
+
+    public int getVHeightPxs() {
+        return vHeightPxs;
+    }
+
+    public float getX0() {
+        return x0;
+    }
+
+    public float getY0() {
+        return y0;
+    }
+
+    public float getGWidth() {
+        return gWidth;
+    }
+
+    /*
+    **********************************************************************
+    *
+    *                           SETTERS
+    *
+    **********************************************************************
+    */
+
+    public void setXRange(float xMin, float xMax) {
+        this.gWidth = xMax - xMin;
+        this.x0 = xMin + gWidth / 2;
+        this.y0 = 0;
+
+        this.graphView.invalidateGraphs();
+    }
+
+    public void setViewDimensions(@NotNull View view) {
+        this.vWidthPxs = view.getWidth();
+        this.vHeightPxs = view.getHeight();
+
+        this.graphView.invalidateGraphs();
+    }
+
+
+    public void setGWidth(float gWidth) {
+        this.gWidth = gWidth;
+
+        this.graphView.invalidateGraphs();
+    }
+
+    public void setViewDimensions(int vWidthPxs, int vHeightPxs) {
+        this.vWidthPxs = vWidthPxs;
+        this.vHeightPxs = vHeightPxs;
+
+        this.graphView.invalidateGraphs();
+    }
+
+    void setXY(float x0, float y0) {
+        this.x0 = x0;
+        this.y0 = y0;
+    }
+
+    public void increaseXY(float dx, float dy) {
+        this.x0 += dx;
+        this.y0 += dy;
+    }
+}

android-app/src/main/java/org/solovyev/android/calculator/plot/Graph3dView.java

@@ -173,8 +173,8 @@ public class Graph3dView extends GLView implements GraphView {
     }
 
     @Override
-    public void init(@NotNull FunctionViewDef functionViewDef) {
+    public void init(@NotNull PlotViewDef plotViewDef) {
-        this.graphViewHelper = GraphViewHelper.newInstance(functionViewDef, Collections.<PlotFunction>emptyList());
+        this.graphViewHelper = GraphViewHelper.newInstance(plotViewDef, Collections.<PlotFunction>emptyList());
     }
 
     @Override
@@ -191,7 +191,13 @@ public class Graph3dView extends GLView implements GraphView {
         isDirty = true;
     }
 
-	@Override
+    @NotNull
+    @Override
+    public List<PlotFunction> getPlotFunctions() {
+        return this.graphViewHelper.getPlotFunctions();
+    }
+
+    @Override
 	public void setXRange(float xMin, float xMax) {
 		//To change body of implemented methods use File | Settings | File Templates.
 	}
@@ -216,12 +222,17 @@ public class Graph3dView extends GLView implements GraphView {
         return 0;  //To change body of implemented methods use File | Settings | File Templates.
     }
 
+    @Override
+    public void invalidateGraphs() {
+        //To change body of implemented methods use File | Settings | File Templates.
+    }
+
     @Override
     public void onSurfaceCreated(GL10 gl, int width, int height) {
         gl.glDisable(GL10.GL_DITHER);
         gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
 
-        final int backgroundColor = graphViewHelper.getFunctionViewDef().getBackgroundColor();
+        final int backgroundColor = graphViewHelper.getPlotViewDef().getBackgroundColor();
         gl.glClearColor(Color.red(backgroundColor) / 255f, Color.green(backgroundColor) / 255f, Color.blue(backgroundColor) / 255f, Color.alpha(backgroundColor) / 255f);
 
         gl.glShadeModel(useHighQuality3d ? GL10.GL_SMOOTH : GL10.GL_FLAT);
@@ -248,8 +259,8 @@ public class Graph3dView extends GLView implements GraphView {
         }
         if (isDirty) {
             ensureGraphsSize(gl);
-            for (int i = 0; i < graphViewHelper.getFunctionPlotDefs().size(); i++) {
+            for (int i = 0; i < graphViewHelper.getPlotFunctions().size(); i++) {
-                 graphs.get(i).update(gl, graphViewHelper.getFunctionPlotDefs().get(i), zoomLevel);
+                 graphs.get(i).update(gl, graphViewHelper.getPlotFunctions().get(i), zoomLevel);
 
             }
             isDirty = false;
@@ -308,7 +319,7 @@ public class Graph3dView extends GLView implements GraphView {
     }
 
     private void ensureGraphsSize(@NotNull GL11 gl) {
-        while (graphViewHelper.getFunctionPlotDefs().size() > graphs.size()) {
+        while (graphViewHelper.getPlotFunctions().size() > graphs.size()) {
             graphs.add(new Graph3d(gl, useHighQuality3d));
         }
     }

android-app/src/main/java/org/solovyev/android/calculator/plot/GraphCalculator.java

@@ -0,0 +1,18 @@
+package org.solovyev.android.calculator.plot;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 1/18/13
+ * Time: 8:58 PM
+ */
+public interface GraphCalculator {
+
+    void computeGraph(@NotNull XyFunction f,
+                      float xMin,
+                      float xMax,
+                      @NotNull GraphData graph,
+                      @NotNull GraphsData graphsData,
+                      @NotNull Graph2dDimensions dimensions);
+}

android-app/src/main/java/org/solovyev/android/calculator/plot/GraphCalculatorImpl.java

@@ -0,0 +1,100 @@
+package org.solovyev.android.calculator.plot;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 1/18/13
+ * Time: 8:58 PM
+ */
+public class GraphCalculatorImpl extends AbstractGraphCalculator {
+
+    @Override
+    protected void compute(@NotNull XyFunction f,
+                             float xMin,
+                             float xMax,
+                             float yMin,
+                             float yMax,
+                             @NotNull GraphData graph,
+                             @NotNull Graph2dDimensions dimensions) {
+        graph.push(xMin, (float)f.eval(xMin));
+
+        final float ratio = dimensions.getGraphToViewRatio();
+        final float maxStep = 15.8976f * ratio;
+        final float minStep = .05f * ratio;
+
+        float yTheta = ratio;
+        yTheta = yTheta * yTheta;
+
+
+        float leftX;
+        float leftY;
+
+        float rightX = graph.getLastX();
+        float rightY = graph.getLastY();
+
+        while (true) {
+            leftX = rightX;
+            leftY = rightY;
+
+            if (leftX > xMax) {
+                break;
+            }
+
+            if (next.empty()) {
+                float x = leftX + maxStep;
+                next.push(x, (float) f.eval(x));
+            }
+
+            rightX = next.getLastX();
+            rightY = next.getLastY();
+            next.pop();
+
+            if (Float.isNaN(leftY) || Float.isNaN(rightY)) {
+                continue;
+            }
+
+            float dx = rightX - leftX;
+            float middleX = (leftX + rightX) / 2;
+            float middleY = (float) f.eval(middleX);
+
+            boolean middleIsOutside = (middleY < leftY && middleY < rightY) || (leftY < middleY && rightY < middleY);
+
+            if (dx < minStep) {
+                // Calculator.log("minStep");
+                if (middleIsOutside) {
+                    graph.push(rightX, Float.NaN);
+                }
+                graph.push(rightX, rightY);
+                continue;
+            }
+
+            if (middleIsOutside && ((leftY < yMin && rightY > yMax) || (leftY > yMax && rightY < yMin))) {
+                graph.push(rightX, Float.NaN);
+                graph.push(rightX, rightY);
+                // Calculator.log("+-inf");
+                continue;
+            }
+
+            if (!middleIsOutside) {
+                if (distance2(leftX, leftY, rightX, rightY, middleY) < yTheta) {
+                    graph.push(rightX, rightY);
+                    continue;
+                }
+            }
+
+            next.push(rightX, rightY);
+            next.push(middleX, middleY);
+            rightX = leftX;
+            rightY = leftY;
+        }
+    }
+
+    // distance as above when x==(x1+x2)/2.
+    private float distance2(float x1, float y1, float x2, float y2, float y) {
+        final float dx = x2 - x1;
+        final float dy = y2 - y1;
+        final float up = dx * (y1 + y2 - y - y);
+        return up * up / (dx * dx + dy * dy);
+    }
+}

android-app/src/main/java/org/solovyev/android/calculator/plot/GraphData.java

@@ -1,5 +1,3 @@
-// Copyright (C) 2009 Mihai Preda
-
 package org.solovyev.android.calculator.plot;
 
 import org.jetbrains.annotations.NotNull;
@@ -39,7 +37,7 @@ class GraphData {
 
     void push(float x, float y) {
         if (size >= allocatedSize) {
-            makeSpace(size + 1);
+            makeSpaceAtTheEnd(size + 1);
         }
 
         xs[size] = x;
@@ -47,9 +45,9 @@ class GraphData {
         ++size;
     }
 
-    private void makeSpace(int spaceSize) {
+    private void makeSpaceAtTheEnd(int newSize) {
         int oldAllocatedSize = allocatedSize;
-        while (spaceSize > allocatedSize) {
+        while (newSize > allocatedSize) {
             allocatedSize += allocatedSize;
         }
 
@@ -63,19 +61,20 @@ class GraphData {
         }
     }
 
-    float topX() {
+
+    float getLastX() {
         return xs[size - 1];
     }
 
-    float topY() {
+    float getLastY() {
         return ys[size - 1];
     }
 
-    float firstX() {
+    float getFirstX() {
         return xs[0];
     }
 
-    float firstY() {
+    float getFirstY() {
         return ys[0];
     }
 
@@ -115,36 +114,27 @@ class GraphData {
         }
     }
 
-    int findPosAfter(float x, float y) {
+    int findPositionAfter(float x, float y) {
-        int pos = 0;
+        int position = 0;
-        while (pos < size && xs[pos] <= x) {
+        while (position < size && xs[position] <= x) {
-            ++pos;
+            ++position;
         }
+
         if (Float.isNaN(y)) {
-            while (pos < size && ys[pos] != ys[pos]) {
+            while (position < size && Float.isNaN(ys[position])) {
-                ++pos;
+                ++position;
             }
         }
-        // Calculator.log("pos " + pos);
+
-        return pos;
+        return position;
     }
 
-    void append(GraphData d) {
+    void append(GraphData that) {
-        makeSpace(size + d.size);
+        makeSpaceAtTheEnd(size + that.size);
-        int pos = d.findPosAfter(xs[size - 1], ys[size - 1]);
+        int position = that.findPositionAfter(xs[size - 1], ys[size - 1]);
-        /*
+        System.arraycopy(that.xs, position, xs, size, that.size - position);
-        while (pos < d.size && d.xs[pos] <= last) {
+        System.arraycopy(that.ys, position, ys, size, that.size - position);
-            ++pos;
+        size += that.size - position;
-        }
-        if (last != last) {
-            while (pos < d.size && d.ys[pos] != d.ys[pos]) {
-                ++pos;
-            }
-        }
-        */
-        System.arraycopy(d.xs, pos, xs, size, d.size - pos);
-        System.arraycopy(d.ys, pos, ys, size, d.size - pos);
-        size += d.size - pos;
     }
 
     public String toString() {

android-app/src/main/java/org/solovyev/android/calculator/plot/GraphView.java

@@ -1,5 +1,3 @@
-// Copyright (C) 2009-2010 Mihai Preda
-
 package org.solovyev.android.calculator.plot;
 
 import android.graphics.Bitmap;
@@ -10,10 +8,13 @@ import java.util.List;
 
 public interface GraphView extends ZoomButtonsController.OnZoomListener, TouchHandler.TouchHandlerListener {
 
-    public void init(@NotNull FunctionViewDef functionViewDef);
+    public void init(@NotNull PlotViewDef plotViewDef);
 
     public void setPlotFunctions(@NotNull List<PlotFunction> plotFunctions);
 
+    @NotNull
+    public List<PlotFunction> getPlotFunctions();
+
     public void onPause();
     public void onResume();
 
@@ -30,6 +31,8 @@ public interface GraphView extends ZoomButtonsController.OnZoomListener, TouchHa
 
     float getYMax();
 
+    void invalidateGraphs();
+
 /*	void increaseDensity();
 	void decreaseDensity();*/
 

android-app/src/main/java/org/solovyev/android/calculator/plot/GraphViewHelper.java

@@ -13,10 +13,10 @@ import java.util.List;
 public class GraphViewHelper {
 
     @NotNull
-    private FunctionViewDef functionViewDef = FunctionViewDef.newDefaultInstance();
+    private PlotViewDef plotViewDef = PlotViewDef.newDefaultInstance();
 
     @NotNull
-    private List<PlotFunction> functionPlotDefs = Collections.emptyList();
+    private List<PlotFunction> plotFunctions = Collections.emptyList();
 
     private GraphViewHelper() {
     }
@@ -27,12 +27,12 @@ public class GraphViewHelper {
     }
 
     @NotNull
-    public static GraphViewHelper newInstance(@NotNull FunctionViewDef functionViewDef,
+    public static GraphViewHelper newInstance(@NotNull PlotViewDef plotViewDef,
                                               @NotNull List<PlotFunction> plotFunctions) {
         final GraphViewHelper result = new GraphViewHelper();
 
-        result.functionViewDef = functionViewDef;
+        result.plotViewDef = plotViewDef;
-        result.functionPlotDefs = Collections.unmodifiableList(plotFunctions);
+        result.plotFunctions = Collections.unmodifiableList(plotFunctions);
 
         return result;
     }
@@ -41,19 +41,19 @@ public class GraphViewHelper {
     public GraphViewHelper copy(@NotNull List<PlotFunction> plotFunctions) {
         final GraphViewHelper result = new GraphViewHelper();
 
-        result.functionViewDef = functionViewDef;
+        result.plotViewDef = plotViewDef;
-        result.functionPlotDefs = Collections.unmodifiableList(plotFunctions);
+        result.plotFunctions = Collections.unmodifiableList(plotFunctions);
 
         return result;
     }
 
     @NotNull
-    public List<PlotFunction> getFunctionPlotDefs() {
+    public List<PlotFunction> getPlotFunctions() {
-        return functionPlotDefs;
+        return plotFunctions;
     }
 
     @NotNull
-    public FunctionViewDef getFunctionViewDef() {
+    public PlotViewDef getPlotViewDef() {
-        return functionViewDef;
+        return plotViewDef;
     }
 }

android-app/src/main/java/org/solovyev/android/calculator/plot/GraphsData.java

@@ -0,0 +1,88 @@
+package org.solovyev.android.calculator.plot;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * User: serso
+ * Date: 1/18/13
+ * Time: 8:32 PM
+ */
+public class GraphsData {
+
+    @NotNull
+    private final GraphView graphView;
+
+    @NotNull
+    private List<GraphData> graphs;
+
+    private float lastXMin;
+    private float lastXMax;
+
+    private float lastYMin;
+
+    private float lastYMax;
+
+    public GraphsData(@NotNull GraphView graphView) {
+        this.graphView = graphView;
+        graphs = new ArrayList<GraphData>(graphView.getPlotFunctions().size());
+    }
+
+    public void clear() {
+        for (GraphData graph : graphs) {
+            graph.clear();
+        }
+
+        while (graphView.getPlotFunctions().size() > graphs.size()) {
+            graphs.add(GraphData.newEmptyInstance());
+        }
+
+        lastYMin = 0;
+        lastYMax = 0;
+    }
+
+    @NotNull
+    public List<GraphData> getGraphs() {
+        return graphs;
+    }
+
+    public float getLastXMin() {
+        return lastXMin;
+    }
+
+    public float getLastXMax() {
+        return lastXMax;
+    }
+
+    public float getLastYMin() {
+        return lastYMin;
+    }
+
+    public float getLastYMax() {
+        return lastYMax;
+    }
+
+    void checkBoundaries(float graphHeight, float yMin, float yMax) {
+        if (yMin < lastYMin || yMax > lastYMax) {
+            float halfGraphHeight = graphHeight / 2;
+            clear();
+            lastYMin = yMin - halfGraphHeight;
+            lastYMax = yMax + halfGraphHeight;
+        }
+    }
+
+    public void setLastXMin(float lastXMin) {
+        this.lastXMin = lastXMin;
+    }
+
+    public void setLastXMax(float lastXMax) {
+        this.lastXMax = lastXMax;
+    }
+
+    @NotNull
+    public GraphData get(int i) {
+        return this.graphs.get(i);
+    }
+}

android-app/src/main/java/org/solovyev/android/calculator/plot/MyGraphicalView.java

@@ -1,25 +0,0 @@
-package org.solovyev.android.calculator.plot;
-
-import android.content.Context;
-import android.graphics.Canvas;
-import org.achartengine.GraphicalView;
-import org.achartengine.chart.AbstractChart;
-import org.solovyev.android.calculator.Locator;
-
-public class MyGraphicalView extends GraphicalView {
-
-	private static final String TAG = MyGraphicalView.class.getSimpleName();
-
-	public MyGraphicalView(Context context, AbstractChart chart) {
-		super(context, chart);
-	}
-
-	@Override
-	protected void onDraw(Canvas canvas) {
-		try {
-			super.onDraw(canvas);
-		} catch (RuntimeException e) {
-			Locator.getInstance().getLogger().error(TAG, e.getMessage(), e);
-		}
-	}
-}

android-app/src/main/java/org/solovyev/android/calculator/plot/MyXYSeries.java

@@ -1,258 +0,0 @@
-/*
- * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
- * For more information, please, contact se.solovyev@gmail.com
- * or visit http://se.solovyev.org
- */
-
-package org.solovyev.android.calculator.plot;
-
-import org.achartengine.model.XYSeries;
-import org.achartengine.util.MathHelper;
-
-import java.util.*;
-
-/**
- * User: serso
- * Date: 12/5/11
- * Time: 8:43 PM
- */
-
-/**
- * BEST SOLUTION IS TO MODIFY LIBRARY CLASS
- * NOTE: this class is a copy of XYSeries with some modifications:
- * 1. Possibility to insert point in th emiddle og the range
- */
-
-public class MyXYSeries extends XYSeries {
-	/**
-	 * The series title.
-	 */
-	private String mTitle;
-	/**
-	 * A list to contain the values for the X axis.
-	 */
-	private List<Double> mX = new ArrayList<Double>();
-	/**
-	 * A list to contain the values for the Y axis.
-	 */
-	private List<Double> mY = new ArrayList<Double>();
-	/**
-	 * The minimum value for the X axis.
-	 */
-	private double mMinX = MathHelper.NULL_VALUE;
-	/**
-	 * The maximum value for the X axis.
-	 */
-	private double mMaxX = -MathHelper.NULL_VALUE;
-	/**
-	 * The minimum value for the Y axis.
-	 */
-	private double mMinY = MathHelper.NULL_VALUE;
-	/**
-	 * The maximum value for the Y axis.
-	 */
-	private double mMaxY = -MathHelper.NULL_VALUE;
-	/**
-	 * The scale number for this series.
-	 */
-	private int mScaleNumber;
-
-	/**
-	 * Builds a new XY series.
-	 *
-	 * @param title the series title.
-	 */
-	public MyXYSeries(String title) {
-		this(title, 10);
-	}
-
-	public MyXYSeries(String title, int initialCapacity) {
-		super(title, 0);
-
-		this.mX = new ArrayList<Double>(initialCapacity);
-		this.mY = new ArrayList<Double>(initialCapacity);
-
-		mTitle = title;
-		mScaleNumber = 0;
-
-		initRange();
-	}
-
-	public int getScaleNumber() {
-		return mScaleNumber;
-	}
-
-	/**
-	 * Initializes the range for both axes.
-	 */
-	private void initRange() {
-		mMinX = MathHelper.NULL_VALUE;
-		mMaxX = -MathHelper.NULL_VALUE;
-		mMinY = MathHelper.NULL_VALUE;
-		mMaxY = -MathHelper.NULL_VALUE;
-		int length = getItemCount();
-		for (int k = 0; k < length; k++) {
-			double x = getX(k);
-			double y = getY(k);
-			updateRange(x, y);
-		}
-	}
-
-	/**
-	 * Updates the range on both axes.
-	 *
-	 * @param x the new x value
-	 * @param y the new y value
-	 */
-	private void updateRange(double x, double y) {
-		mMinX = Math.min(mMinX, x);
-		mMaxX = Math.max(mMaxX, x);
-		mMinY = Math.min(mMinY, y);
-		mMaxY = Math.max(mMaxY, y);
-	}
-
-	/**
-	 * Returns the series title.
-	 *
-	 * @return the series title
-	 */
-	public String getTitle() {
-		return mTitle;
-	}
-
-	/**
-	 * Sets the series title.
-	 *
-	 * @param title the series title
-	 */
-	public void setTitle(String title) {
-		mTitle = title;
-	}
-
-	/**
-	 * Adds a new value to the series.
-	 *
-	 * @param x the value for the X axis
-	 * @param y the value for the Y axis
-	 */
-	public void add(double x, double y) {
-		boolean added = false;
-		for (int i = 0; i < mX.size(); i++ ) {
-			if ( mX.get(i) > x ) {
-				mX.add(i, x);
-				mY.add(i, y);
-				added = true;
-				break;
-			}
-		}
-
-		if ( !added ) {
-			mX.add(x);
-			mY.add(y);
-		}
-
-		updateRange(x, y);
-	}
-
-
-	public boolean needToAdd(double density, double x) {
-		boolean result = true;
-
-		for (Double x1 : mX) {
-			if (Math.abs(x - x1) < density) {
-				result = false;
-				break;
-			}
-		}
-
-		return result;
-	}
-
-	/**
-	 * Removes an existing value from the series.
-	 *
-	 * @param index the index in the series of the value to remove
-	 */
-	public void remove(int index) {
-		double removedX = mX.remove(index);
-		double removedY = mY.remove(index);
-		if (removedX == mMinX || removedX == mMaxX || removedY == mMinY || removedY == mMaxY) {
-			initRange();
-		}
-	}
-
-	/**
-	 * Removes all the existing values from the series.
-	 */
-	public void clear() {
-		mX.clear();
-		mY.clear();
-		initRange();
-	}
-
-	/**
-	 * Returns the X axis value at the specified index.
-	 *
-	 * @param index the index
-	 * @return the X value
-	 */
-	public double getX(int index) {
-		return mX.get(index);
-	}
-
-	/**
-	 * Returns the Y axis value at the specified index.
-	 *
-	 * @param index the index
-	 * @return the Y value
-	 */
-	public double getY(int index) {
-		return mY.get(index);
-	}
-
-	/**
-	 * Returns the series item count.
-	 *
-	 * @return the series item count
-	 */
-	public int getItemCount() {
-		return mX == null ? 0 : mX.size();
-	}
-
-	/**
-	 * Returns the minimum value on the X axis.
-	 *
-	 * @return the X axis minimum value
-	 */
-	public double getMinX() {
-		return mMinX;
-	}
-
-	/**
-	 * Returns the minimum value on the Y axis.
-	 *
-	 * @return the Y axis minimum value
-	 */
-	public double getMinY() {
-		return mMinY;
-	}
-
-	/**
-	 * Returns the maximum value on the X axis.
-	 *
-	 * @return the X axis maximum value
-	 */
-	public double getMaxX() {
-		return mMaxX;
-	}
-
-	/**
-	 * Returns the maximum value on the Y axis.
-	 *
-	 * @return the Y axis maximum value
-	 */
-	public double getMaxY() {
-		return mMaxY;
-	}
-}
-

android-app/src/main/java/org/solovyev/android/calculator/plot/PlotViewDef.java

@@ -8,7 +8,7 @@ import org.jetbrains.annotations.NotNull;
  * Date: 1/5/13
  * Time: 9:11 PM
  */
-public class FunctionViewDef {
+public class PlotViewDef {
 
     /*
     **********************************************************************
@@ -38,10 +38,10 @@ public class FunctionViewDef {
 
     private int backgroundColor = DEFAULT_BACKGROUND_COLOR;
 
-    private FunctionViewDef() {
+    private PlotViewDef() {
     }
 
-    private FunctionViewDef(int axisColor, int axisLabelColor, int gridColor, int backgroundColor) {
+    private PlotViewDef(int axisColor, int axisLabelColor, int gridColor, int backgroundColor) {
         this.axisColor = axisColor;
         this.axisLabelsColor = axisLabelColor;
         this.gridColor = gridColor;
@@ -49,13 +49,13 @@ public class FunctionViewDef {
     }
 
     @NotNull
-    public static FunctionViewDef newDefaultInstance() {
+    public static PlotViewDef newDefaultInstance() {
-        return new FunctionViewDef();
+        return new PlotViewDef();
     }
 
     @NotNull
-    public static FunctionViewDef newInstance(int axisColor, int axisLabelColor, int gridColor, int backgroundColor) {
+    public static PlotViewDef newInstance(int axisColor, int axisLabelColor, int gridColor, int backgroundColor) {
-        return new FunctionViewDef(axisColor, axisLabelColor, gridColor, backgroundColor);
+        return new PlotViewDef(axisColor, axisLabelColor, gridColor, backgroundColor);
     }
 
     public int getAxisColor() {

android-app/src/test/java/org/solovyev/android/calculator/plot/PlotUtilsTest.java

@@ -1,47 +0,0 @@
-/*
- * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
- * For more information, please, contact se.solovyev@gmail.com
- * or visit http://se.solovyev.org
- */
-
-package org.solovyev.android.calculator.plot;
-
-import jscl.math.Expression;
-import jscl.math.function.Constant;
-import junit.framework.Assert;
-import org.achartengine.model.XYSeries;
-import org.jetbrains.annotations.NotNull;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-/**
- * User: serso
- * Date: 12/5/11
- * Time: 9:07 PM
- */
-public class PlotUtilsTest {
-
-	@Test
-	public void testAddXY() throws Exception {
-		MyXYSeries series = new MyXYSeries("test_01", 100);
-		PlotUtils.addXY(-10, 10, Expression.valueOf("asin(t)"), new Constant("t"), series, new MyXYSeries("test_01_imag"), false, 200);
-		testAscSeries(series);
-		PlotUtils.addXY(-1, 1, Expression.valueOf("asin(t)"), new Constant("t"), series, new MyXYSeries("test_01_imag"), true, 200);
-		testAscSeries(series);
-
-		series = new MyXYSeries("test_02", 1000);
-		PlotUtils.addXY(-10, 10, Expression.valueOf("1/t"), new Constant("t"), series, new MyXYSeries("test_01_imag"), false, 1000);
-		testAscSeries(series);
-		PlotUtils.addXY(-1, 1, Expression.valueOf("1/t"), new Constant("t"), series, new MyXYSeries("test_01_imag"), true, 1000);
-		testAscSeries(series);
-
-	}
-
-	public void testAscSeries(@NotNull XYSeries series) {
-		for ( int i = 0; i < series.getItemCount(); i++ ) {
-			if (i > 1) {
-				Assert.assertTrue(series.getX(i - 1) + " > " +series.getX(i) + " at " + i + " of " + series.getItemCount(), series.getX(i - 1) <= series.getX(i));
-			}
-		}
-	}
-}