Package uk.ac.starlink.ttools.plot
Class XYStats
java.lang.Object
uk.ac.starlink.ttools.plot.XYStats
Calculates X-Y correlation statistics.
- Since:
- 15 Jul 2004
- Author:
- Mark Taylor (Starlink)
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Constructor Summary
ConstructorsConstructorDescriptionXYStats
(boolean xLog, boolean yLog) Constructs a new correlation statistics calculator. -
Method Summary
Modifier and TypeMethodDescriptionvoid
addPoint
(double x, double y) Submits a data point for calculations.double
Returns the product moment correlation coefficient.double[]
Returns the polynomial coefficients of a linear regression line for the submitted data.double[]
Calculates the linear regression line for the submitted points.
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Constructor Details
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XYStats
public XYStats(boolean xLog, boolean yLog) Constructs a new correlation statistics calculator.- Parameters:
xLog
- whether the X coordinates are being plotted on a logarithmic scaleyLog
- whether the Y coordinates are being plotted on a logarithmic scale
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Method Details
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addPoint
public void addPoint(double x, double y) Submits a data point for calculations.- Parameters:
x
- X coordinatey
- Y coordinate
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getLinearCoefficients
public double[] getLinearCoefficients()Returns the polynomial coefficients of a linear regression line for the submitted data.- Returns:
- 2-element array: (intercept, gradient)
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getCorrelation
public double getCorrelation()Returns the product moment correlation coefficient.- Returns:
- correlation coefficient
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linearRegressionLine
public double[] linearRegressionLine()Calculates the linear regression line for the submitted points. The endpoints of the line correspond to the lowest and highest X values submitted.- Returns:
- 4-element array giving the endpoints (low-X, low-Y, high-X, high-Y) of a linear regression line for these data
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