edu.mines.jtk.dsp

Class LinearInterpolator

java.lang.Object

edu.mines.jtk.dsp.LinearInterpolator

public class LinearInterpolator
extends java.lang.Object

A linear interpolator for uniformly-sampled functions y(x). Interpolation of functions y(x1,x2) is bi-linear. Interpolation of functions y(x1,x2,x3) is tri-linear.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LinearInterpolator.Extrapolation The method used to extrapolate samples when interpolating.

Constructor Summary

Constructors

Constructor and Description
LinearInterpolator()

Method Summary

Methods

Modifier and Type	Method and Description
LinearInterpolator.Extrapolation	getExtrapolation() Gets the extrapolation method for this interpolator.
float	interpolate(double x) Interpolates the current uniform samples as real numbers.
float	interpolate(double x1, double x2) Interpolates the current uniform samples as real numbers.
float	interpolate(double x1, double x2, double x3) Interpolates the current uniform samples as real numbers.
void	interpolate(int nx, double dx, double fx, float[] y) Interpolates the current uniform samples as real numbers.
void	interpolate(int nx, float[] x, float[] y) Interpolates the current uniform samples as real numbers.
void	setExtrapolation(LinearInterpolator.Extrapolation extrap) Sets the extrapolation method for this interpolator.
void	setUniform(int nxu, double dxu, double fxu, float[] yu) Sets the current sampling and samples for a function y(x).
void	setUniform(int nx1u, double dx1u, double fx1u, int nx2u, double dx2u, double fx2u, float[][] yu) Sets the current sampling and samples for a function y(x1,x2).
void	setUniform(int nx1u, double dx1u, double fx1u, int nx2u, double dx2u, double fx2u, int nx3u, double dx3u, double fx3u, float[][][] yu) Sets the current sampling and samples for a function y(x1,x2,x3).
void	setUniformSamples(float[] yu) Sets the current samples for a uniformly-sampled function y(x).
void	setUniformSamples(float[][] yu) Sets the current samples for a uniformly-sampled function y(x1,x2).
void	setUniformSamples(float[][][] yu) Sets the current samples for a uniformly-sampled function y(x1,x2,x3).
void	setUniformSampling(int nxu, double dxu, double fxu) Sets the current sampling for a uniformly-sampled function y(x).
void	setUniformSampling(int nx1u, double dx1u, double fx1u, int nx2u, double dx2u, double fx2u) Sets the current sampling for a uniformly-sampled function y(x1,x2).
void	setUniformSampling(int nx1u, double dx1u, double fx1u, int nx2u, double dx2u, double fx2u, int nx3u, double dx3u, double fx3u) Sets the current sampling for a uniformly-sampled function y(x1,x2,x3).

Methods inherited from class java.lang.Object

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

Constructor Detail

LinearInterpolator

public LinearInterpolator()

Method Detail

getExtrapolation

public LinearInterpolator.Extrapolation getExtrapolation()

Gets the extrapolation method for this interpolator.

Returns:

the extrapolation method.

setExtrapolation

public void setExtrapolation(LinearInterpolator.Extrapolation extrap)

Sets the extrapolation method for this interpolator. The default extrapolation method is extrapolation with zeros.

Parameters:

extrap - the extrapolation method.

setUniformSampling

public void setUniformSampling(int nxu,
                      double dxu,
                      double fxu)

Sets the current sampling for a uniformly-sampled function y(x). In some applications, this sampling never changes, and this method may be called only once for this interpolator.

Parameters:

nxu - the number of uniform samples.

dxu - the uniform sampling interval.

fxu - the value x corresponding to the first uniform sample yu[0].

setUniformSamples

public void setUniformSamples(float[] yu)

Sets the current samples for a uniformly-sampled function y(x). If sample values are complex numbers, real and imaginary parts are packed in the array as real, imaginary, real, imaginary, and so on.

Sample values are passed by reference, not by copy. Changes to sample values in the specified array will yield changes in interpolated values.

Parameters:

yu - array[nxu] of uniform samples of y(x); by reference, not by copy.

setUniform

public void setUniform(int nxu,
              double dxu,
              double fxu,
              float[] yu)

Sets the current sampling and samples for a function y(x). This method simply calls the two methods setUniformSampling(int,double,double) and setUniformSamples(float[]) with the specified parameters.

Parameters:

nxu - the number of uniform samples.

dxu - the uniform sampling interval.

fxu - the value x corresponding to the first uniform sample yu[0].

yu - array[nxu] of uniform samples of y(x); by reference, not by copy.

interpolate

public float interpolate(double x)

Interpolates the current uniform samples as real numbers.

Parameters:

x - the value x at which to interpolate y(x).

Returns:

the interpolated y(x).

interpolate

public void interpolate(int nx,
               float[] x,
               float[] y)

Interpolates the current uniform samples as real numbers.

Parameters:

nx - the number of output samples.

x - array[nx] of values x at which to interpolate y(x).

y - array[nx] of interpolated output y(x).

interpolate

public void interpolate(int nx,
               double dx,
               double fx,
               float[] y)

Interpolates the current uniform samples as real numbers.

This method does not perform any anti-alias filtering, which may or may not be necessary to avoid aliasing when the specified output sampling interval exceeds the current uniform sampling interval.

Parameters:

nx - the number of output samples.

dx - the output sampling interval.

fx - the value x corresponding to the first output sample y[0].

y - array[nx] of interpolated output y(x).

setUniformSampling

public void setUniformSampling(int nx1u,
                      double dx1u,
                      double fx1u,
                      int nx2u,
                      double dx2u,
                      double fx2u)

Sets the current sampling for a uniformly-sampled function y(x1,x2). In some applications, this sampling never changes, and this method may be called only once for this interpolator.

Parameters:

nx1u - the number of uniform samples in 1st dimension.

dx1u - the uniform sampling interval in 1st dimension.

fx1u - the value x1 correponding to the first sample yu[0][0].

nx2u - the number of uniform samples in 2nd dimension.

dx2u - the uniform sampling interval in 2nd dimension.

fx2u - the value x2 correponding to the first sample yu[0][0].

setUniformSamples

public void setUniformSamples(float[][] yu)

Sets the current samples for a uniformly-sampled function y(x1,x2). If sample values are complex numbers, real and imaginary parts are packed in the array as real, imaginary, real, imaginary, and so on.

Sample values are passed by reference, not by copy. Changes to sample values in the specified array will yield changes in interpolated values.

Parameters:

yu - array[nx2u][nx1u] of samples of y(x1,x2); by reference, not by copy.

setUniform

public void setUniform(int nx1u,
              double dx1u,
              double fx1u,
              int nx2u,
              double dx2u,
              double fx2u,
              float[][] yu)

Sets the current sampling and samples for a function y(x1,x2). This method simply calls the two methods setUniformSampling(int,double,double,int,double,double) and setUniformSamples(float[][]) with the specified parameters.

Parameters:

nx1u - the number of uniform samples in 1st dimension.

dx1u - the uniform sampling interval in 1st dimension.

fx1u - the value x1 correponding to the first sample yu[0][0].

nx2u - the number of uniform samples in 2nd dimension.

dx2u - the uniform sampling interval in 2nd dimension.

fx2u - the value x2 correponding to the first sample yu[0][0].

yu - array[nx2u][nx1u] of samples of y(x1,x2); by reference, not by copy.

interpolate

public float interpolate(double x1,
                double x2)

Interpolates the current uniform samples as real numbers.

Parameters:

x1 - the value x1 at which to interpolate y(x1,x2).

x2 - the value x2 at which to interpolate y(x1,x2).

Returns:

the interpolated y(x1,x2).

setUniformSampling

public void setUniformSampling(int nx1u,
                      double dx1u,
                      double fx1u,
                      int nx2u,
                      double dx2u,
                      double fx2u,
                      int nx3u,
                      double dx3u,
                      double fx3u)

Sets the current sampling for a uniformly-sampled function y(x1,x2,x3). In some applications, this sampling never changes, and this method may be called only once for this interpolator.

Parameters:

nx1u - the number of uniform samples in 1st dimension.

dx1u - the uniform sampling interval in 1st dimension.

fx1u - the value x1 correponding to the first sample yu[0][0][0].

nx2u - the number of uniform samples in 2nd dimension.

dx2u - the uniform sampling interval in 2nd dimension.

fx2u - the value x2 correponding to the first sample yu[0][0][0].

nx3u - the number of uniform samples in 3rd dimension.

dx3u - the uniform sampling interval in 3rd dimension.

fx3u - the value x3 correponding to the first sample yu[0][0][0].

setUniformSamples

public void setUniformSamples(float[][][] yu)

Sets the current samples for a uniformly-sampled function y(x1,x2,x3). If sample values are complex numbers, real and imaginary parts are packed in the array as real, imaginary, real, imaginary, and so on.

Sample values are passed by reference, not by copy. Changes to sample values in the specified array will yield changes in interpolated values.

Parameters:

yu - array[nx3u][nx2u][nx1u] of samples of y(x1,x2,x3); by reference, not by copy.

setUniform

public void setUniform(int nx1u,
              double dx1u,
              double fx1u,
              int nx2u,
              double dx2u,
              double fx2u,
              int nx3u,
              double dx3u,
              double fx3u,
              float[][][] yu)

Sets the current sampling and samples for a function y(x1,x2,x3). This method simply calls the two methods setUniformSampling( int,double,double,int,double,double,int,double,double) and setUniformSamples(float[][][]) with the specified parameters.

Parameters:

nx1u - the number of uniform samples in 1st dimension.

dx1u - the uniform sampling interval in 1st dimension.

fx1u - the value x1 correponding to the first sample yu[0][0][0].

nx2u - the number of uniform samples in 2nd dimension.

dx2u - the uniform sampling interval in 2nd dimension.

fx2u - the value x2 correponding to the first sample yu[0][0][0].

nx3u - the number of uniform samples in 3rd dimension.

dx3u - the uniform sampling interval in 3rd dimension.

fx3u - the value x3 correponding to the first sample yu[0][0][0].

yu - array[nx3u][nx2u][nx1u] of samples of y(x1,x2,x3); by reference, not by copy.

interpolate

public float interpolate(double x1,
                double x2,
                double x3)

Interpolates the current uniform samples as real numbers.

Parameters:

x1 - the value x1 at which to interpolate y(x1,x2,x3).

x2 - the value x2 at which to interpolate y(x1,x2,x3).

x3 - the value x3 at which to interpolate y(x1,x2,x3).

Returns:

the interpolated y(x1,x2,x3).