umontreal.iro.lecuyer.charts
Class QQPlot

java.lang.Object
  umontreal.iro.lecuyer.charts.XYChart
      umontreal.iro.lecuyer.charts.XYLineChart
          umontreal.iro.lecuyer.charts.QQPlot

public class QQPlot
extends XYLineChart

This class implements QQ-plot (or quantile-quantile plot) objects that compare two probability distributions. The data is given as a list of x-coordinates (x₁, x₂,…, x_n), and one is given a reference continuous probability distribution F(x). One first sorts the x_i in ascending order, then noted x_(i), and plots the points (F^-1(p_i), x_(i)), where i = 1, 2,…, n and p_i = (i - 1/2)/n, to see if the data x_i comes from the reference distribution F(x). The graph of the straight line y = x is also plotted for comparison.

Constructor Summary

QQPlot(String title, String XLabel, String YLabel, ContinuousDistribution dist, double[] X)
Constructs a new QQPlot instance using the points X.

QQPlot(String title, String XLabel, String YLabel, ContinuousDistribution dist, double[][] data, int r)
Constructs a new QQPlot instance.

QQPlot(String title, String XLabel, String YLabel, ContinuousDistribution dist, double[] X, int numPoints)
Similar to the constructor QQPlot(title, XLabel, YLabel, dist, X) above, except that only the first numPoints of X are plotted.

Method Summary

Methods inherited from class umontreal.iro.lecuyer.charts.XYLineChart

add, add, add, add, add, getSeriesCollection, setSeriesCollection, setTicksSynchro, toLatex, view, viewBar

Methods inherited from class umontreal.iro.lecuyer.charts.XYChart

disableGrid, drawVerticalLine, enableGrid, getChartMargin, getJFreeChart, getTitle, getXAxis, getYAxis, setAutoRange, setAutoRange, setAutoRange00, setChartMargin, setLatexDocFlag, setManualRange, setManualRange, setManualRange00, setprobFlag, setTitle, toLatexFile

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QQPlot

public QQPlot(String title,
              String XLabel,
              String YLabel,
              ContinuousDistribution dist,
              double[] X)

Constructs a new QQPlot instance using the points X. title is a title, XLabel is a short description of the x-axis, and YLabel a short description of the y-axis. The plot is a QQ-plot of the points (F^-1(p_i), x_(i)), i = 1, 2,…, n, where p_i = (i - 1/2)/n, x_i = X[i-1], x_(i) are the sorted points, and x = F^-1(p) = dist.inverseF(p). The points X are not sorted.

Parameters:

title - chart title.

XLabel - Label on x-axis.

YLabel - Label on y-axis.

dist - Reference distribution

X - points.

QQPlot

public QQPlot(String title,
              String XLabel,
              String YLabel,
              ContinuousDistribution dist,
              double[] X,
              int numPoints)

Similar to the constructor QQPlot(title, XLabel, YLabel, dist, X) above, except that only the first numPoints of X are plotted.

Parameters:

title - chart title.

XLabel - Label on x-axis.

YLabel - Label on y-axis.

dist - Reference distribution

X - point set.

numPoints - number of points to plot

QQPlot

public QQPlot(String title,
              String XLabel,
              String YLabel,
              ContinuousDistribution dist,
              double[][] data,
              int r)

Constructs a new QQPlot instance. title is a title, XLabel is a short description of the x-axis, and YLabel a short description of the y-axis. The input vectors in data represents several sets of x-points. r determine the set of points to be plotted in the QQ-plot, that is, one will plot only the points data[r][i], for i = 0, 1,…,(n - 1) and a given r, where n is the number of points in set r. The points are assumed to follow the distribution dist.

Parameters:

title - chart title.

XLabel - Label on x-axis.

YLabel - Label on y-axis.

dist - Reference distribution

data - series of point sets.

r - set of points to plot