/** FunctionPlotter written 2004 by Jakob Magiera jakob@magiera.net **/ import java.util.*; import java.awt.*; import java.awt.event.*; import java.applet.*; import java.text.*; public class FunctionPlotter extends Applet implements ActionListener, MouseListener, ItemListener { private double startX = -5.0d; private double endX = 5.0d; private double stepX = 0.05d; private double maxY = 0.0d; private double minY = 0.0d; private int mouseX = 0; private int mouseY = 0; private boolean showCoords = false; private boolean showDeriv1 = false; private boolean showDeriv2 = false; private CalcTree functionTree = null; // GUI Fields private Font textFont = new Font("SansSerif", Font.PLAIN, 10); private GridBagLayout gridBagL; private GridBagLayout gridBagL2; private GridBagLayout gridBagL3; private GridBagConstraints gbc; private DrawingPanel drawingArea; private Panel inputPanel; private Panel optionPanel; private Label inputLabelFunction; private Label inputLabelStartX; private Label inputLabelEndX; private Label inputLabelStepX; private Label inputLabelZoom; private Label inputLabelShift; private TextField inputAreaFunction; private TextField inputAreaStartX; private TextField inputAreaEndX; private TextField inputAreaStepX; private TextArea outputArea; private Button plotButton; private Button zoomInButton; private Button zoomOutButton; private Button shiftLeftButton; private Button shiftRightButton; private Checkbox deriv1Checkbox; private Checkbox deriv2Checkbox; public void init() { gridBagL = new GridBagLayout(); gridBagL2 = new GridBagLayout(); gridBagL3 = new GridBagLayout(); gbc = new GridBagConstraints(); drawingArea = new DrawingPanel(); drawingArea.addMouseListener(this); inputPanel = new Panel(); optionPanel = new Panel(); inputLabelFunction = new Label("f(x)="); inputLabelStartX = new Label("start:"); inputLabelEndX = new Label("end:"); inputLabelStepX = new Label("step:"); inputLabelZoom = new Label("zoom:"); inputLabelShift = new Label("shift:"); inputAreaFunction = new TextField("atan(x)"); inputAreaStartX = new TextField(""+startX); inputAreaEndX = new TextField(""+endX); String stepString = ""+stepX; inputAreaStepX = new TextField(stepString); outputArea = new TextArea("",5,5,TextArea.SCROLLBARS_BOTH); outputArea.setEditable(false); plotButton = new Button("plot!"); plotButton.addActionListener(this); zoomInButton = new Button("+"); zoomInButton.addActionListener(this); zoomOutButton = new Button("-"); zoomOutButton.addActionListener(this); shiftLeftButton = new Button("<"); shiftLeftButton.addActionListener(this); shiftRightButton = new Button(">"); shiftRightButton.addActionListener(this); deriv1Checkbox = new Checkbox("plot 1st derivative",false); deriv2Checkbox = new Checkbox("plot 2nd derivative",false); deriv1Checkbox.addItemListener(this); deriv2Checkbox.addItemListener(this); setLayout(gridBagL); inputPanel.setLayout(gridBagL2); optionPanel.setLayout(gridBagL3); // format input panel buildConstraints(gbc,0,0,1,1,1.1,0.0,GridBagConstraints.EAST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputLabelFunction,gbc); inputPanel.add(inputLabelFunction); buildConstraints(gbc,1,0,1,1,6.0,0.0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL); gridBagL2.setConstraints(inputAreaFunction,gbc); inputPanel.add(inputAreaFunction); buildConstraints(gbc,2,0,1,1,1.0,0.0,GridBagConstraints.EAST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputLabelStartX,gbc); inputPanel.add(inputLabelStartX); buildConstraints(gbc,3,0,1,1,1.0,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputAreaStartX,gbc); inputPanel.add(inputAreaStartX); buildConstraints(gbc,4,0,1,1,1.0,0.0,GridBagConstraints.EAST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputLabelEndX,gbc); inputPanel.add(inputLabelEndX); buildConstraints(gbc,5,0,1,1,1.0,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputAreaEndX,gbc); inputPanel.add(inputAreaEndX); buildConstraints(gbc,6,0,1,1,1.0,0.0,GridBagConstraints.EAST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputLabelStepX,gbc); inputPanel.add(inputLabelStepX); buildConstraints(gbc,7,0,1,1,1.0,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputAreaStepX,gbc); inputPanel.add(inputAreaStepX); buildConstraints(gbc,8,0,1,1,0.1,0.0,GridBagConstraints.EAST,GridBagConstraints.NONE); gridBagL2.setConstraints(plotButton,gbc); inputPanel.add(plotButton); buildConstraints(gbc,9,0,1,1,0.5,0.0,GridBagConstraints.EAST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputLabelZoom,gbc); inputPanel.add(inputLabelZoom); buildConstraints(gbc,10,0,1,1,0.1,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL2.setConstraints(zoomInButton,gbc); inputPanel.add(zoomInButton); buildConstraints(gbc,11,0,1,1,0.1,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL2.setConstraints(zoomOutButton,gbc); inputPanel.add(zoomOutButton); buildConstraints(gbc,12,0,1,1,1.0,0.0,GridBagConstraints.EAST,GridBagConstraints.NONE); gridBagL2.setConstraints(inputLabelShift,gbc); inputPanel.add(inputLabelShift); buildConstraints(gbc,13,0,1,1,0.1,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL2.setConstraints(shiftLeftButton,gbc); inputPanel.add(shiftLeftButton); buildConstraints(gbc,14,0,1,1,0.1,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL2.setConstraints(shiftRightButton,gbc); inputPanel.add(shiftRightButton); // format option panel buildConstraints(gbc,0,0,1,1,0.1,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL3.setConstraints(deriv1Checkbox,gbc); optionPanel.add(deriv1Checkbox); buildConstraints(gbc,1,0,1,1,0.1,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE); gridBagL3.setConstraints(deriv2Checkbox,gbc); optionPanel.add(deriv2Checkbox); // drawing area buildConstraints(gbc,0,0,1,1,1.0,9.0,GridBagConstraints.WEST,GridBagConstraints.BOTH); gridBagL.setConstraints(drawingArea,gbc); add(drawingArea); // input panel buildConstraints(gbc,0,1,1,1,1.0,0.0,GridBagConstraints.WEST,GridBagConstraints.BOTH); gridBagL.setConstraints(inputPanel,gbc); add(inputPanel); // option panel buildConstraints(gbc,0,2,1,1,1.0,0.0,GridBagConstraints.WEST,GridBagConstraints.BOTH); gridBagL.setConstraints(optionPanel,gbc); add(optionPanel); // output area buildConstraints(gbc,0,3,1,1,1.0,0.0,GridBagConstraints.WEST,GridBagConstraints.BOTH); gridBagL.setConstraints(outputArea,gbc); add(outputArea); // set the background color drawingArea.setBackground(new Color(0.8f,0.8f,0.8f)); inputPanel.setBackground(new Color(0.8f,0.8f,0.8f)); inputLabelFunction.setBackground(new Color(0.8f,0.8f,0.8f)); inputLabelStartX.setBackground(new Color(0.8f,0.8f,0.8f)); inputLabelEndX.setBackground(new Color(0.8f,0.8f,0.8f)); inputLabelStepX.setBackground(new Color(0.8f,0.8f,0.8f)); // calculate the first tree try { functionTree = buildTree(inputAreaFunction.getText()); } catch (ScanException se) { output(se.getMessage()); } } public void output(String s) { outputArea.append(s+"\n"); } public void start() { } public void stop() { } public void actionPerformed(ActionEvent e) { String cmd = e.getActionCommand(); try { startX = Double.parseDouble(inputAreaStartX.getText()); } catch (NumberFormatException nfe ) { output("wrong number format in 'start'"); } try { endX = Double.parseDouble(inputAreaEndX.getText()); } catch (NumberFormatException nfe ) { output("wrong number format in 'end'"); } try { stepX = Double.parseDouble(inputAreaStepX.getText()); } catch (NumberFormatException nfe ) { output("wrong number format in 'step'"); } double spanX = Math.abs(endX-startX); if ( cmd.equals("+") ) { // zoom in startX += spanX*0.05; endX -= spanX*0.05; inputAreaStartX.setText(""+startX); inputAreaEndX.setText(""+endX); } else if ( cmd.equals("-") ) { // zoom out startX -= spanX*0.05; endX += spanX*0.05; inputAreaStartX.setText(""+startX); inputAreaEndX.setText(""+endX); } else if ( cmd.equals("<") ) { // shift left startX -= spanX*0.05; endX -= spanX*0.05; inputAreaStartX.setText(""+startX); inputAreaEndX.setText(""+endX); } else if ( cmd.equals(">") ) { // shift right startX += spanX*0.05; endX += spanX*0.05; inputAreaStartX.setText(""+startX); inputAreaEndX.setText(""+endX); } try { functionTree = buildTree(inputAreaFunction.getText()); //output("Tree:"+functionTree.getStringTraverse()); } catch(ScanException se) { output(se.getMessage()); } drawingArea.repaint(); } public void mouseClicked(MouseEvent e) { } public void mouseEntered(MouseEvent e) { } public void mouseExited(MouseEvent e) { } public void mouseMoved(MouseEvent e) { } public void mousePressed(MouseEvent e) { mouseX = e.getX(); mouseY = e.getY(); showCoords = true; drawingArea.repaint(); } public void mouseReleased(MouseEvent e) { showCoords = false; drawingArea.repaint(); } public void itemStateChanged(ItemEvent e) { if ( e.getItem().equals("plot 1st derivative") ) { showDeriv1 = e.getStateChange() == ItemEvent.SELECTED; } else if ( e.getItem().equals("plot 2nd derivative") ) { showDeriv2 = e.getStateChange() == ItemEvent.SELECTED; } drawingArea.repaint(); } ///////////////////////////// // internal methods ///////////////////////////// private void buildConstraints(GridBagConstraints gbc,int x,int y, int width, int height,double weightx, double weighty, int anchor,int fill){ gbc.gridx = x; gbc.gridy = y; gbc.gridwidth = width; gbc.gridheight = height; gbc.weightx = weightx; gbc.weighty = weighty; gbc.fill = fill; gbc.anchor = anchor; gbc.ipady = 5; } private CalcTree buildTree(String function) throws ScanException { // clean function of any spaces function = function.replaceAll("\\s+",""); CalcTree tree = new CalcTree(); CalcTree currentTree = tree; String nextNumber = ""; String nextOperator = ""; boolean numDone = false; boolean op1Done = false; boolean op2Done = false; boolean skipMode = false; // needed for parentheses for(int i=0; i= function.length() ) { break; } s = ""+function.charAt(i); } i--; numDone = true; } else if ( s.equals("x") ) { numDone = true; nextNumber = s; } else if ( s.equals("E") ) { numDone = true; nextNumber = s; } else if ( s.equals("+") ) { op2Done = true; nextOperator = s; } else if ( s.equals("-") ) { op2Done = true; nextOperator = s; } else if ( s.equals("*") ) { op2Done = true; nextOperator = s; } else if ( s.equals("/") ) { op2Done = true; nextOperator = s; } else if ( s.equals("^") ) { op2Done = true; nextOperator = s; } else if ( s.matches("[sincotaqrlge]") ) { while(s.matches("[sincotaqrlge]")) { nextOperator += s; i++; if ( i >= function.length() ) { break; } s = ""+function.charAt(i); } op1Done = true; i--; } else if ( s.equals("P") ) { nextNumber += s; i++; s = ""+function.charAt(i); if(s.equals("I")) { nextNumber += s; } numDone = true; } else { throw new ScanException("Unknown symbol: "+s); } if ( skipMode ) { nextNumber = ""; nextOperator = ""; continue; } if ( numDone && ! nextNumber.equals("") ) { OperatorNode node = new OperatorNode(OperatorNode.TYPE_NUMBER,nextNumber); if ( currentTree.getContents() != null ) { if ( currentTree.getContents().type == OperatorNode.TYPE_UNARY_OPERATOR ) { currentTree.getRight().setContents(node); } else { currentTree.setContents(node); } } else { currentTree.setContents(node); } numDone = false; nextNumber = ""; } if ( op2Done && ! nextOperator.equals("") ) { // create a new opNode with the current Operator OperatorNode nodeContents = new OperatorNode(OperatorNode.TYPE_BINARY_OPERATOR,nextOperator); // create a new treeNode that contains the opNode CalcTree node = new CalcTree(); node.setContents(nodeContents); // set the left part to be the currentTree node.setLeft(currentTree); // right part is a new tree node.setRight(new CalcTree()); node.getRight().setParent(node); // if the currentTree had a parent node, // let the new node have this parent now if ( currentTree.getParent() != null ) { currentTree.getParent().setRight(node); node.setParent(currentTree.getParent()); } else { tree = node; } currentTree.setParent(node); currentTree = node.getRight(); op2Done = false; nextOperator = ""; } if ( op1Done && ! nextOperator.equals("") ) { // create a new opNode with the current Operator OperatorNode nodeContents = new OperatorNode(OperatorNode.TYPE_UNARY_OPERATOR,nextOperator); // create a new treeNode that contains the opNode CalcTree node = new CalcTree(); node.setContents(nodeContents); // set the right part to be the currentTree node.setRight(currentTree); // right part is a new tree node.setLeft(new CalcTree()); node.getLeft().setParent(node); // if the currentTree had a parent node, // let the new node have this parent now if ( currentTree.getParent() != null ) { currentTree.getParent().setRight(node); node.setParent(currentTree.getParent()); } else { tree = node; } currentTree.setParent(node); currentTree = node; op1Done = false; nextOperator = ""; } } return tree; } ///////////////////////////// // internal classes ///////////////////////////// private class DrawingPanel extends Panel { public void paint(Graphics g) { g.setFont(textFont); double sizeY = getHeight(); double sizeX = getWidth(); double spanX = Math.abs(endX-startX); g.setColor(Color.black); maxY = 0.0d; minY = 0.0d; // step optimization // to avoid too small/big steps if ( spanX/stepX > sizeX ) { stepX = spanX/sizeX; inputAreaStepX.setText(""+stepX); } if ( spanX/stepX < sizeX/4 ) { stepX = 2*spanX/sizeX; inputAreaStepX.setText(""+stepX); } // first get maxY and minY int nvalues = (int)Math.round(spanX/stepX) + 1; double values[] = new double[nvalues]; int count = 0; for(double x=startX; x<=endX; x += stepX) { double y = 0.0; try { y = functionTree.calculateTraverse(x); } catch( CalcException ce) { output(ce.getMessage()); break; } //output("x:"+x+" y:"+y); values[count] = y; if ( y > maxY ) { maxY = y; } if ( y < minY ) { minY = y; } count++; } // avoid too small y span double spanY = Math.abs(minY-maxY); if ( spanY < 1.0d ) { minY = minY -1.0d; maxY = maxY + 1.0d; spanY = Math.abs(minY-maxY); } // draw the axes // x-axis double yPercent = 1-(-minY)/spanY; int yPoint = (int)((sizeY-1)*yPercent); g.drawLine(0,yPoint, (int)sizeX-1, yPoint); // y-axis double xPercent = (-startX)/spanX; int xPoint = (int)((sizeX-1)*xPercent); g.drawLine(xPoint,0, xPoint, (int)sizeY-1); // draw min value on y-axis g.drawLine(xPoint-2, (int)sizeY-1, xPoint+2, (int)sizeY-1); String stringValue = ""+minY; g.drawString(stringValue,xPoint+2,(int)sizeY-1); // draw max value on y-axis g.drawLine(xPoint-2,0, xPoint+2, 0); stringValue = ""+maxY; g.drawString(stringValue,xPoint+2,10); // draw min value on x-axis g.drawLine(0,yPoint-2, 0, yPoint+2); stringValue = ""+startX; g.drawString(stringValue,0,yPoint-2); // draw max value on x-axis g.drawLine((int)sizeX-1, yPoint-2, (int)sizeX-1, yPoint+2); stringValue = ""+endX; // calculate width of string Graphics2D g2d = (Graphics2D)g; java.awt.geom.Rectangle2D rect = textFont.getStringBounds(stringValue,0,stringValue.length(),g2d.getFontRenderContext()); // and draw it at the appropriate position g.drawString(stringValue,(int)sizeX-(int)rect.getWidth()-1,yPoint-2); // then plot the curve count = 0; int pointsX[] = new int[nvalues]; int pointsY[] = new int[nvalues]; int pointsYD1[] = new int[nvalues]; int pointsYD2[] = new int[nvalues]; double valuesD1[] = new double[nvalues]; double valuesD2[] = new double[nvalues]; for(double x=startX; x<=endX; x += stepX) { g.setColor(Color.red); double y = values[count]; double percentX = (x-startX)/spanX; int pointX = (int)(sizeX*percentX); double percentY = 1 - (y-minY)/spanY; int pointY = (int)(sizeY*percentY); pointsX[count] = pointX; pointsY[count] = pointY; if ( count > 0 ) { g.drawLine(pointX,pointY,pointsX[count-1],pointsY[count-1]); } else { g.drawRect(pointX,pointY,0,0); } // plot the first and second derivative if ( showDeriv1 || showDeriv2 ) { valuesD1[count] = y; valuesD2[count] = valuesD1[count]; if ( count > 0 ) { valuesD1[count] = (y-values[count-1]) / stepX; if ( showDeriv2 ) { valuesD2[count] = (valuesD1[count]-valuesD1[count-1]) / stepX; } } double percentYD1 = 1 - (valuesD1[count]-minY)/spanY; pointsYD1[count] = (int)(sizeY*percentYD1); if ( showDeriv2 ) { double percentYD2 = 1 - (valuesD2[count]-minY)/spanY; pointsYD2[count] = (int)(sizeY*percentYD2); } if ( count > 1 ) { if ( showDeriv1 ) { g.setColor(Color.blue); g.drawLine(pointX,pointsYD1[count],pointsX[count-1],pointsYD1[count-1]); } if ( showDeriv2 ) { g.setColor(Color.green); g.drawLine(pointX,pointsYD2[count],pointsX[count-1],pointsYD2[count-1]); } } else { if ( showDeriv1 ) { g.setColor(Color.blue); g.drawRect(pointX,pointsYD1[count],0,0); } if ( showDeriv2 ) { g.setColor(Color.green); g.drawRect(pointX,pointsYD2[count],0,0); } } } // if the mouse is pressed and near the curve, // show the coordinates if ( showCoords ) { g.setColor(Color.black); // main curve String coords = ""; yPoint = 0; if ( Math.abs(pointX-mouseX) < 2 && Math.abs(pointY-mouseY) < 4 ) { coords = "x="+x+" y="+values[count]; yPoint = pointY; } // 1st derivative if ( showDeriv1 && Math.abs(pointX-mouseX) < 2 && Math.abs(pointsYD1[count]-mouseY) < 4 ) { coords = "x="+x+" y="+valuesD1[count]; yPoint = pointsYD1[count]; } // 2nd derivative if ( showDeriv2 && Math.abs(pointX-mouseX) < 2 && Math.abs(pointsYD2[count]-mouseY) < 4 ) { coords = "x="+x+" y="+valuesD2[count]; yPoint = pointsYD2[count]; } //output("mx:"+mouseX+" my:"+mouseY+" x:"+pointX+" y:"+pointY); // calculate width of string rect = textFont.getStringBounds(coords,0,coords.length(),g2d.getFontRenderContext()); int xdiff = 0; int ydiff = 0; // make sure it's not drawn outside the panel if ( yPoint - rect.getHeight() < 0 ) { ydiff = (int)rect.getHeight(); } if ( pointX + rect.getWidth() > sizeX-1 ) { xdiff = (int)rect.getWidth(); } // draw the coords g.drawString(coords,pointX-xdiff,yPoint+ydiff); } //output(/*"x:"+x+"y:"+y+*/"sx:"+sizeX+" sy:"+sizeY+" px:"+pointX+"py:"+pointY); count++; } } } }