edu.mines.jtk.interp

Class PolyTrend2

java.lang.Object

edu.mines.jtk.interp.PolyTrend2

public class PolyTrend2
extends java.lang.Object

A low-order polynomial trend in scattered data f(x1,x2). The trend is computed by least-squares fitting of the scattered data values. This class enables the computed trend to be easily removed from scattered data and restored to interpolated data.

Constructor Summary

Constructors

Constructor and Description
PolyTrend2(int order, float[] f, float[] x1, float[] x2) Constructs a trend with specified scattered samples.

Method Summary

Methods

Modifier and Type	Method and Description
void	detrend() Removes this trend from its referenced scattered sample values.
void	detrend(float[][] f, Sampling s1, Sampling s2) Removes this trend from the specified samples.
void	detrend(float[] f, float[] x1, float[] x2) Removes this trend from the specified samples.
float	detrend(float f, float x1, float x2) Removes this trend from the specified sample.
void	restore() Restores this trend to its referenced scattered sample valuess.
void	restore(float[][] f, Sampling s1, Sampling s2) Restores this trend to the specified samples.
void	restore(float[] f, float[] x1, float[] x2) Restores this trend to the specified samples.
float	restore(float f, float x1, float x2) Restores this trend to the specified sample.
void	setSamples(float[] f, float[] x1, float[] x2) Sets the known (scattered) samples to be fit.

Methods inherited from class java.lang.Object

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

Constructor Detail

PolyTrend2

public PolyTrend2(int order,
          float[] f,
          float[] x1,
          float[] x2)

Constructs a trend with specified scattered samples. The specified arrays are referenced; not copied.

If insufficient samples are available for the specified order, then a fit is performed with a polynomial of lower order than that specified. Note that an order zero (constant) polynomial fit is always possible when at least one sample is specified.

Parameters:

order - order of polynomial; must be 0, 1, or 2.

f - array of sample values f(x1,x2).

x1 - array of sample x1 coordinates.

x2 - array of sample x2 coordinates.

Method Detail

setSamples

public void setSamples(float[] f,
              float[] x1,
              float[] x2)

Sets the known (scattered) samples to be fit. The specified arrays are referenced, not copied.

Parameters:

f - array of sample values f(x1,x2).

x1 - array of sample x1 coordinates.

x2 - array of sample x2 coordinates.

detrend

public void detrend()

Removes this trend from its referenced scattered sample values. Modifies values in the array f referenced by this trend.

Throws:

java.lang.IllegalStateException - if the trend has already been removed.

restore

public void restore()

Restores this trend to its referenced scattered sample valuess. Modifies values in the array f referenced by this trend.

Throws:

java.lang.IllegalStateException - if the trend has not yet been removed.

detrend

public float detrend(float f,
            float x1,
            float x2)

Removes this trend from the specified sample.

Parameters:

f - the sample value.

x1 - the sample x1 coordinate.

x2 - the sample x2 coordinate.

Returns:

the sample value with trend removed.

restore

public float restore(float f,
            float x1,
            float x2)

Restores this trend to the specified sample.

Parameters:

f - the sample value.

x1 - the sample x1 coordinate.

x2 - the sample x2 coordinate.

Returns:

the sample value with trend restored.

detrend

public void detrend(float[] f,
           float[] x1,
           float[] x2)

Removes this trend from the specified samples.

Parameters:

f - array of sample values to be detrended.

x1 - array of sample x1 coordinates.

x2 - array of sample x2 coordinates.

restore

public void restore(float[] f,
           float[] x1,
           float[] x2)

Restores this trend to the specified samples.

Parameters:

f - array of sample values to be restored.

x1 - array of sample x1 coordinates.

x2 - array of sample x2 coordinates.

detrend

public void detrend(float[][] f,
           Sampling s1,
           Sampling s2)

Removes this trend from the specified samples.

Parameters:

f - array of sample values to be detrended.

s1 - sampling of x1 coordinates.

s2 - sampling of x2 coordinates.

restore

public void restore(float[][] f,
           Sampling s1,
           Sampling s2)

Restores this trend to the specified samples.

Parameters:

f - array of sample values to be restored.

s1 - sampling of x1 coordinates.

s2 - sampling of x2 coordinates.