ptolemy.plot
Class Histogram

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--java.awt.Panel
                    |
                    +--ptolemy.plot.PlotBox
                          |
                          +--ptolemy.plot.Histogram

public class Histogram

extends PlotBox

A histogram plotter. The plot can be configured and data can be provided either through a file with commands or through direct invocation of the public methods of the class. To read a file or a URL, use the read() method.

When calling the public methods, in most cases the changes will not be visible until paint() has been called. To request that this be done, call repaint(). One exception is addPoint(), which makes the affect of the new point visible immediately if the plot is visible on the screen.

The ASCII format for the file file contains any number commands, one per line. Unrecognized commands and commands with syntax errors are ignored. Comments are denoted by a line starting with a pound sign "#". The recognized commands include those supported by the base class, plus a few more. The commands are case insensitive, but are usually capitalized. The number of data sets to be plotted does not need to be specified. Data sets are added as needed. Each dataset is identified with a color (see the base class).

The appearance of the histogram can be altered by the following commands:

 Bars: width
 Bars: width, offset
 

The width is a real number specifying the width of the bars as a fraction of the bin width. It usually has a value less than or equal to one, and defaults to 0.5. The offset is a real number specifying how much the bar of the i < /i>^th data set is offset from the previous one. This allows bars to "peek out" from behind the ones in front. It defaults to 0.15. Note that the frontmost data set will be the first one.

The width of each bin of the histogram can be specified using:

 BinWidth: width
 

This is given in whatever units the data has. By default, each bin is centered at x = nw, where w is the width of the bin and n is an integer. That bin represents values in the range (x - w/2, x + w/2). The alignment of the bins can be changed with the following command:

 BinOffset: offset
 

If this method is used with argument o, then each bin is centered at x = nw + o, and represents values in the range (x - w/2 + o, x + w/2 + o). So for example, if o = w/2, then each bin represents values from nw to (n + 1)w) for some integer n. The default offset is 0.5, half the default bin width.

To specify data to be plotted, start a data set with the following command:

 DataSet: string
 

Here, string is a label that will appear in the legend. It is not necessary to enclose the string in quotation marks. To start a new dataset without giving it a name, use:

 DataSet:
 

In this case, no item will appear in the legend. New datasets are plotted behind the previous ones. The data itself is given by a sequence of numbers, one per line. The numbers are specified as strings that can be parsed by the Double parser in Java. It is also possible to specify the numbers using all the formats accepted by the Plot class, so that the same data may be plotted by both classes. The x data is ignored, and only the y data is used to calculate the histogram.

Version:

$Id: Histogram.java,v 1.10 1999/08/11 23:27:41 cxh Exp $

Author:

Edward A. Lee

See Also:

Serialized Form

Inner classes inherited from class ptolemy.plot.PlotBox

PlotBox.DragListener, PlotBox.ZoomListener

Field Summary

protected int	_currentdataset
protected java.util.Vector	_histogram
protected boolean	_painted
protected java.util.Vector	_points

Fields inherited from class ptolemy.plot.PlotBox

_background, _bottomPadding, _colors, _documentBase, _foreground, _grid, _height, _leftPadding, _LOG10SCALE, _lrx, _lry, _PADDING, _rangesGivenByZooming, _rightPadding, _topPadding, _ulx, _uly, _usecolor, _width, _wrap, _xBottom, _xhighgiven, _xlog, _xlowgiven, _xMax, _xMin, _xRangeGiven, _xscale, _xTop, _yBottom, _yhighgiven, _ylog, _ylowgiven, _yMax, _yMin, _yRangeGiven, _yscale, _yTop

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Constructor Summary

Histogram()

Method Summary

protected void	_checkDatasetIndex(int dataset) Check the argument to ensure that it is a valid data set index.
protected void	_drawBar(java.awt.Graphics graphics, int dataset, long xpos, long ypos, boolean clip) Draw bar from the specified point to the y axis.
protected void	_drawPlot(java.awt.Graphics graphics, boolean clearfirst) Draw the axes and then plot the histogram.
protected boolean	_parseLine(java.lang.String line) Parse a line that gives plotting information.
protected void	_write(java.io.PrintWriter output) Write plot information to the specified output stream.
void	addLegend(int dataset, java.lang.String legend) Add a legend (displayed at the upper right) for the specified data set with the specified string.
void	addPoint(int dataset, double value) In the specified data set, add the specified value to the histogram.
void	addPoint(int dataset, double x, double y, boolean connected) In the specified data set, add the specified y value to the histogram.
void	clear(boolean format) Clear the plot of all data points.
void	samplePlot() Create a sample plot.
void	setBars(double width, double offset) Set the width and offset of the bars.
void	setBinOffset(double offset) Set the offset of the bins, in whatever units the data are given.
void	setBinWidth(double width) Set the width of the bins, in whatever units the data are given.

Methods inherited from class ptolemy.plot.PlotBox

_drawPoint, _help, _setButtonsVisibility, _writeOldSyntax, addXTick, addYTick, export, fillPlot, getColor, getColorByName, getDataurl, getDocumentBase, getGrid, getLegend, getMinimumSize, getPreferredSize, getTitle, getXLabel, getXLog, getXRange, getXTicks, getYLabel, getYLog, getYRange, getYTicks, init, paint, parseFile, parseFile, read, read, setBackground, setBounds, setButtons, setColor, setDataurl, setDocumentBase, setForeground, setGrid, setLabelFont, setSize, setTitle, setTitleFont, setWrap, setXLabel, setXLog, setXRange, setYLabel, setYLog, setYRange, update, write, write, writeOldSyntax, zoom

Methods inherited from class java.awt.Panel

addNotify

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getInsets, getLayout, getMaximumSize, insets, invalidate, isAncestorOf, layout, list, list, locate, minimumSize, paintComponents, paramString, preferredSize, print, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setCursor, setFont, setLayout, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addPropertyChangeListener, addPropertyChangeListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, getBackground, getBounds, getBounds, getColorModel, getComponentOrientation, getCursor, getDropTarget, getFont, getFontMetrics, getForeground, getGraphics, getHeight, getInputContext, getInputMethodRequests, getLocale, getLocation, getLocation, getLocationOnScreen, getName, getParent, getPeer, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isDisplayable, isDoubleBuffered, isEnabled, isFocusTraversable, isLightweight, isOpaque, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, remove, removeComponentListener, removeFocusListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, reshape, resize, resize, setBounds, setComponentOrientation, setDropTarget, setEnabled, setLocale, setLocation, setLocation, setName, setSize, setVisible, show, show, size, toString, transferFocus

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

_currentdataset

protected int _currentdataset

_points

protected java.util.Vector _points

_histogram

protected java.util.Vector _histogram

_painted

protected boolean _painted

Constructor Detail

Histogram

public Histogram()

Method Detail

addLegend

public void addLegend(int dataset,
                      java.lang.String legend)

Add a legend (displayed at the upper right) for the specified data set with the specified string. Short strings generally fit better than long strings.

Overrides:

addLegend in class PlotBox

Parameters:

dataset - The dataset index.

legend - The label for the dataset.

addPoint

public void addPoint(int dataset,
                     double value)

In the specified data set, add the specified value to the histogram. Data set indices begin with zero. If the data set does not exist, create it. The new point will visibly alter the histogram if the plot is visible on the screen. Otherwise, it will be drawn the next time the histogram is drawn on the screen.

Parameters:

dataset - The data set index.

value - The new value.

addPoint

public void addPoint(int dataset,
                     double x,
                     double y,
                     boolean connected)

In the specified data set, add the specified y value to the histogram. The x value and the connected arguments are ignored. Data set indices begin with zero. If the data set does not exist, create it.

Parameters:

dataset - The data set index.

x - Ignored.

y - The Y position of the new point.

connected - Ignored

clear

public void clear(boolean format)

Clear the plot of all data points. If the argument is true, then reset all parameters to their initial conditions, including the persistence, plotting format, and axes formats. For the change to take effect, you must call repaint().

Overrides:

clear in class PlotBox

Parameters:

format - If true, clear the format controls as well.

samplePlot

public void samplePlot()

Create a sample plot.

Overrides:

samplePlot in class PlotBox

setBars

public void setBars(double width,
                    double offset)

Set the width and offset of the bars. Both are specified as a fraction of a bin width. The offset is the amount by which the i < sup>th data set is shifted to the right, so that it peeks out from behind the earlier data sets.

Parameters:

width - The width of the bars.

offset - The offset per data set.

setBinOffset

public void setBinOffset(double offset)

Set the offset of the bins, in whatever units the data are given. Without calling this, each bin is centered at x = nw, where w is the width of the bin and n is an integer. That bin represents values in the range (x - w/2, x + w/2). If this method is called with argument o, then each bin is centered at x = nw + o, and represents values in the range (x - w/2 + o, x + w/2 + o). So for example, if o = w/2, then each bin represents values from nw to (n + 1)w) for some integer n.

Parameters:

offset - The bin offset.

setBinWidth

public void setBinWidth(double width)

Set the width of the bins, in whatever units the data are given.

Parameters:

width - The width of the bins.

_checkDatasetIndex

protected void _checkDatasetIndex(int dataset)

Check the argument to ensure that it is a valid data set index. If it is less than zero, throw an IllegalArgumentException (which is a runtime exception). If it does not refer to an existing data set, then fill out the _points and _histogram Vectors so that they refer to all existing data sets.

Parameters:

dataset - The data set index.

_drawBar

protected void _drawBar(java.awt.Graphics graphics,
                        int dataset,
                        long xpos,
                        long ypos,
                        boolean clip)

Draw bar from the specified point to the y axis. If the specified point is below the y axis or outside the x range, do nothing. If the clip argument is true, then do not draw above the y range. Note that paint() should be called before calling this method so that _xscale and _yscale are properly set.

Parameters:

graphics - The graphics context.

dataset - The index of the dataset.

xpos - The x position.

ypos - The y position.

clip - If true, then do not draw outside the range.

_drawPlot

protected void _drawPlot(java.awt.Graphics graphics,
                         boolean clearfirst)

Draw the axes and then plot the histogram. This is synchronized to prevent multiple threads from drawing the histogram at the same time. It sets _painted true and calls notifyAll() at the end so that a thread can use wait() to prevent it plotting points before the axes have been first drawn. If the second argument is true, clear the display first. This method is called by paint(). To cause it to be called you would normally call repaint(), which eventually causes paint() to be called.

Overrides:

_drawPlot in class PlotBox

Parameters:

graphics - The graphics context.

clearfirst - If true, clear the plot before proceeding.

_parseLine

protected boolean _parseLine(java.lang.String line)

Parse a line that gives plotting information. Return true if the line is recognized. Lines with syntax errors are ignored.

Overrides:

_parseLine in class PlotBox

Parameters:

line - A command line.

Returns:

True if the line is recognized.

_write

protected void _write(java.io.PrintWriter output)

Write plot information to the specified output stream. Derived classes should override this method to first call the parent class method, then add whatever additional information they wish to add to the stream.

Overrides:

_write in class PlotBox

Parameters:

output - A buffered print writer.