How to emphasize a xypoint ?

[Clemens Schmitt]

I got a given row of date sorted values and I am visualizing this in a xyplot.
The problem is that I want to emphasize this given x/y points with a symbol e.g. a triangle or a rectangle around each point.

Is there anybody who can help me?

Thanks.

Clemens Schmitt

[David Gilbert]

Hi Clemens,

Thanks for posting your request. I've added it to the JFreeChart tasklist on SourceForge (id = 26480).

Regards,

DG.

[ofir]

Dear all,

my problem is as foloows:

I am using a XYData source, used by a jfree line graph. I want the vertical
axis to be calculated by a auto range mode. for each new value arrives, i set a new
data source to chart ( and making it actually using a "dynamic" data source ).

The problem is that if i get a series of identical values( for example: 4,4,4,... )
the line is lcated in the top of the chart, and you can barely see it.

i get something like this:

__________________________________
4
3
2
1
0 1 2 3 4 5 6 7 8 9 10 11 12 13

how can i still use a auto range mode for the vertical axis, and in addition,
show the line properly. One solution is to add an extra height to the vertical axis
but the value is calculated by an auto mode.

Someone has any idea ?

Thanks alot,
Ofir

[David Gilbert]

If you look at the autoAdjustRange(...) method in the NumberAxis subclasses, you'll see that there is a 5% hard-coded margin added to the axis range (5% above and below the largest and smallest values in the data source). You should change the value to suit your application.

In the next version of JFreeChart there will be methods to set the upper and lower margins for the auto-range calculation. You can see the latest code if you browse through the CVS repository on SourceForge (http://sourceforge.net/projects/jfreechart).

Regards,

DG.

[Daniel Serodio]

I saw on the SourceForget Task manager that "Jeremy Green has sent in some code for this - need to review it and add it to the next version." Is this code in CVS? Where can I get this?

TIA,
Daniel Serodio

[David Gilbert]

Daniel,

Here is the modified LinePlot.java source. I'd like to make the code a little more general before I include it in the JFreeChart release:

/* =======================================
* JFreeChart : a Java Chart Class Library
* =======================================
* Version 0.5.5;
* (C) Copyright 2000, Simba Management Limited;
* Project Lead: David Gilbert (david.gilbert@bigfoot.com);
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with this library;
* if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307, USA.
*
* $Id: LinePlot.java,v 1.1.1.1.2.1 2000/10/24 14:28:41 dgilbert Exp $
*/

package com.jrefinery.chart;

import java.awt.*;
import java.awt.geom.*;
import java.util.*;

/**
* A Plot that displays data in the form of a line chart, using data from any class that
* implements the CategoryDataSource interface.
* @see Plot
* @see CategoryDataSource
*/
public class LinePlot extends Plot implements CategoryPlot, VerticalValuePlot {

/**
* Standard constructor: returns a LinePlot with attributes specified by the caller.
* @param chart The chart that the plot belongs to;
* @param horizontal The horizontal axis;
* @param vertical The vertical axis;
*/

//********************New Code
public static int FILLED = 0;
public static int OUTLINE = 1;

protected boolean useLineDecoration = false;
protected int decorationWidth = 0;
protected int decorationHeight = 0;
protected int decorationStyle = FILLED;

//**********************End New Code

public LinePlot(JFreeChart chart, Axis horizontal, Axis vertical)
throws AxisNotCompatibleException {
super(chart, horizontal, vertical);
}

//**************New Code

public void addCircleDecoration(int width, int height){
useLineDecoration = true;
decorationWidth = width;
decorationHeight = height;
}

//****************End New Code

/**
* A convenience method that returns the data source for the plot, cast as a
* CategoryDataSource.
*/
public CategoryDataSource getDataSource() {
return (CategoryDataSource)chart.getDataSource();
}

/**
* A convenience method that returns a reference to the horizontal axis cast as a
* CategoryAxis.
*/
public CategoryAxis getCategoryAxis() {
return (CategoryAxis)horizontalAxis;
}

/**
* A convenience method that returns a reference to the vertical axis cast as a
* VerticalNumberAxis.
*/
public VerticalNumberAxis getValueAxis() {
return (VerticalNumberAxis)verticalAxis;
}

/**
* A convenience method that returns a list of the categories in the data source.
*/
public java.util.List getCategories() {
return getDataSource().getCategories();
}

/**
* Returns the x-coordinate (in Java 2D User Space) of the center of the specified category.
* @param category The index of the category of interest (first category index = 0);
* @param area The region within which the plot will be drawn.
*/
public double getCategoryCoordinate(int category, Rectangle2D area) {
int categoryCount = getDataSource().getCategoryCount();
return area.getX()+(category+1)*(area.getWidth()/(categoryCount+1));
}

/**
* Returns a list of lines that will fit inside the specified area.
*/
private java.util.List getLines(Rectangle2D plotArea) {

java.util.List lines = new ArrayList();
CategoryDataSource data = getDataSource();
if (data!=null) {
// series, category counts
int categoryCount = data.getCategoryCount();
int seriesCount = data.getSeriesCount();

for (int i=0; i<seriesCount; i++) {
Point2D prev = null;
int categoryIndex = 0;
Iterator iterator = data.getCategories().iterator();
while (iterator.hasNext()) {
Object category = iterator.next();
Number value = data.getValue(i, category);
Paint p = chart.getSeriesPaint(i);
Stroke s = chart.getSeriesStroke(i);
double x = getCategoryCoordinate(categoryIndex, plotArea);
Point2D current = new Point2D.Double(x, getValueAxis().translatedValue(value, plotArea));
if (prev!=null) {
lines.add(new Line(prev.getX(), prev.getY(), current.getX(), current.getY(), s, p));
}
prev = current;
categoryIndex++;
}
prev = null;
}
}
return lines;
}

/**
* Checks the compatibility of a horizontal axis, returning true if the axis is compatible with
* the plot, and false otherwise.
* @param axis The horizontal axis.
*/
public boolean isCompatibleHorizontalAxis(Axis axis) {
if (axis instanceof CategoryAxis) {
return true;
}
else return false;
}

/**
* Checks the compatibility of a vertical axis, returning true if the axis is compatible with
* the plot, and false otherwise.
* @param axis The vertical axis;
*/
public boolean isCompatibleVerticalAxis(Axis axis) {
if (axis instanceof VerticalNumberAxis) {
return true;
}
else return false;
}

/**
* Draws the plot on a Java 2D graphics device (such as the screen or a printer).
* @param g2 The graphics device;
* @param drawArea The area within which the plot should be drawn;
*/
public void draw(Graphics2D g2, Rectangle2D drawArea) {

if (insets!=null) {
drawArea = new Rectangle2D.Double(drawArea.getX()+insets.left,
drawArea.getY()+insets.top,
drawArea.getWidth()-insets.left-insets.right,
drawArea.getHeight()-insets.top-insets.bottom);
}

// we can cast the axes because LinePlot enforces support of these interfaces
HorizontalAxis ha = getHorizontalAxis();
VerticalAxis va = getVerticalAxis();

double h = ha.reserveHeight(g2, this, drawArea);
Rectangle2D vAxisArea = va.reserveAxisArea(g2, this, drawArea, h);

// compute the plot area
Rectangle2D plotArea = new Rectangle2D.Double(drawArea.getX()+vAxisArea.getWidth(),
drawArea.getY(),
drawArea.getWidth()-vAxisArea.getWidth(),
drawArea.getHeight()-h);

drawOutlineAndBackground(g2, plotArea);

// draw the axes
getCategoryAxis().draw(g2, drawArea, plotArea);
getValueAxis().draw(g2, drawArea, plotArea);

Shape originalClip=g2.getClip();
g2.setClip(plotArea);

// draw the lines
java.util.List lines = getLines(plotArea); // area should be remaining area only
for (int i=0; i<lines.size(); i++) {
Line l = (Line)lines.get(i);
g2.setPaint(l.getPaint());
g2.setStroke(l.getStroke());
g2.draw(l.getLine());


//*******New Code*********
if(useLineDecoration){
Line2D realLine = l.getLine();
g2.fill(new Arc2D.Double(realLine.getX2()-(decorationWidth/2),realLine.getY2()-(decorationHeight/2),decorationWidth,decorationHeight,0,360,Arc2D.OPEN));
g2.fill(new Arc2D.Double(realLine.getX1()-(decorationWidth/2),realLine.getY1()-(decorationHeight/2),decorationWidth,decorationHeight,0,360,Arc2D.OPEN));
}
//*********End New Code*******
}

g2.setClip(originalClip);

}

/**
* Returns a short string describing the plot type;
*/
public String getPlotType() {
return "Line Plot";
}

/**
* Returns the minimum value in the range, since this is plotted against the vertical axis for
* BarPlot.
*/
public Number getMinimumVerticalDataValue() {

DataSource data = this.getChart().getDataSource();
if (data!=null) {
return DataSources.getMinimumRangeValue(data);
}
else return null;

}

/**
* Returns the maximum value in either the domain or the range, whichever is displayed against
* the vertical axis for the particular type of plot implementing this interface.
*/
public Number getMaximumVerticalDataValue() {

DataSource data = this.getChart().getDataSource();
if (data!=null) {
return DataSources.getMaximumRangeValue(data);
}
else return null;
}

}

Regards,

DG.