public class LocalCausalFilter
extends java.lang.Object
Local causal filters have coefficients that may vary from one output sample to the next. Such a filter is not shift invariant. Its application is not equivalent to convolution with its impulse response.
Though not shift-invariant, a local causal filter is a linear operator with a corresponding anti-causal transpose (adjoint) operator. A local causal filter may have a causal inverse, and its transpose may have an anti-causal inverse.
A local causal filter is a stable all-zero filter that may or may not be minimum-phase; that is, it may or may not have a causal stable inverse. That inverse is a recursive all-pole filter, as described by Claerbout, J., 1998, Multidimensional recursive filters via a helix: Geophysics, v. 63, n. 5, p. 1532-1541.
The filter and its transpose and inverse may all be applied in-place; that is, the input and output arrays may be the same array. However, the inverse-transpose filter cannot be applied in-place.
Modifier and Type | Class and Description |
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static interface |
LocalCausalFilter.A1
Interface for filter coefficients indexed in 1 dimension.
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static interface |
LocalCausalFilter.A2
Interface for filter coefficients indexed in 2 dimensions.
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static interface |
LocalCausalFilter.A3
Interface for filter coefficients indexed in 3 dimensions.
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Constructor and Description |
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LocalCausalFilter(int[] lag1)
Constructs a local causal filter for specified lag1.
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LocalCausalFilter(int[] lag1,
int[] lag2)
Constructs a local causal filter for specified lag1 and lag2.
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LocalCausalFilter(int[] lag1,
int[] lag2,
int[] lag3)
Constructs a local causal filter for specified lag1, lag2, and lag3.
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Modifier and Type | Method and Description |
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void |
apply(LocalCausalFilter.A1 a1,
float[] x,
float[] y)
Applies this filter.
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void |
apply(LocalCausalFilter.A2 a2,
float[][] x,
float[][] y)
Applies this filter.
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void |
apply(LocalCausalFilter.A3 a3,
float[][][] x,
float[][][] y)
Applies this filter.
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void |
applyInverse(LocalCausalFilter.A1 a1,
float[] y,
float[] x)
Applies the inverse of this filter.
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void |
applyInverse(LocalCausalFilter.A2 a2,
float[][] y,
float[][] x)
Applies the inverse of this filter.
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void |
applyInverse(LocalCausalFilter.A3 a3,
float[][][] y,
float[][][] x)
Applies the inverse of this filter.
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void |
applyInverseTranspose(LocalCausalFilter.A1 a1,
float[] y,
float[] x)
Applies the inverse transpose of this filter.
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void |
applyInverseTranspose(LocalCausalFilter.A2 a2,
float[][] y,
float[][] x)
Applies the inverse transpose of this filter.
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void |
applyInverseTranspose(LocalCausalFilter.A3 a3,
float[][][] y,
float[][][] x)
Applies the inverse transpose of this filter.
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void |
applyTranspose(LocalCausalFilter.A1 a1,
float[] x,
float[] y)
Applies the transpose of this filter.
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void |
applyTranspose(LocalCausalFilter.A2 a2,
float[][] x,
float[][] y)
Applies the transpose of this filter.
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void |
applyTranspose(LocalCausalFilter.A3 a3,
float[][][] x,
float[][][] y)
Applies the transpose of this filter.
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int[] |
getLag1()
Gets a copy of the lags in the 1st dimension.
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int[] |
getLag2()
Gets a copy of the lags in the 2nd dimension.
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int[] |
getLag3()
Gets a copy of the lags in the 3rd dimension.
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public LocalCausalFilter(int[] lag1)
For j=0 only, lag1[j] is zero. All lag1[j] must be non-negative.
lag1
- array of lags.public LocalCausalFilter(int[] lag1, int[] lag2)
For j=0 only, lag1[j] and lag2[j] are zero. All lag2[j] must be non-negative. If lag2[j] is zero, then lag1[j] must be non-negative.
lag1
- array of lags in 1st dimension.lag2
- array of lags in 2nd dimension.public LocalCausalFilter(int[] lag1, int[] lag2, int[] lag3)
For j=0 only, lag1[j] and lag2[j] and lag3[j] are zero. All lag3[j] must be non-negative. If lag3[j] is zero, then lag2[j] must be non-negative. If lag3[j] and lag2[j] are zero, then lag1[j] must be non-negative.
lag1
- array of lags in 1st dimension.lag2
- array of lags in 2nd dimension.lag3
- array of lags in 3rd dimension.public int[] getLag1()
public int[] getLag2()
public int[] getLag3()
public void apply(LocalCausalFilter.A1 a1, float[] x, float[] y)
May be applied in-place; input and output arrays may be the same.
a1
- filter coefficients.x
- input array.y
- output array.public void applyTranspose(LocalCausalFilter.A1 a1, float[] x, float[] y)
May be applied in-place; input and output arrays may be the same.
a1
- filter coefficients.x
- input array.y
- output array.public void applyInverse(LocalCausalFilter.A1 a1, float[] y, float[] x)
May be applied in-place; input and output arrays may be the same.
a1
- filter coefficients.y
- input array.x
- output array.public void applyInverseTranspose(LocalCausalFilter.A1 a1, float[] y, float[] x)
The inverse transpose cannot be applied in-place; input and output arrays cannot be the same array.
a1
- filter coefficients.y
- input array.x
- output array.public void apply(LocalCausalFilter.A2 a2, float[][] x, float[][] y)
May be applied in-place; input and output arrays may be the same.
a2
- filter coefficients.x
- input array.y
- output array.public void applyTranspose(LocalCausalFilter.A2 a2, float[][] x, float[][] y)
May be applied in-place; input and output arrays may be the same.
a2
- filter coefficients.x
- input array.y
- output array.public void applyInverse(LocalCausalFilter.A2 a2, float[][] y, float[][] x)
May be applied in-place; input and output arrays may be the same.
a2
- filter coefficients.y
- input array.x
- output array.public void applyInverseTranspose(LocalCausalFilter.A2 a2, float[][] y, float[][] x)
The inverse transpose cannot be applied in-place; input and output arrays cannot be the same array.
a2
- filter coefficients.y
- input array.x
- output array.public void apply(LocalCausalFilter.A3 a3, float[][][] x, float[][][] y)
May be applied in-place; input and output arrays may be the same.
a3
- filter coefficients.x
- input array.y
- output array.public void applyTranspose(LocalCausalFilter.A3 a3, float[][][] x, float[][][] y)
May be applied in-place; input and output arrays may be the same.
a3
- filter coefficients.x
- input array.y
- output array.public void applyInverse(LocalCausalFilter.A3 a3, float[][][] y, float[][][] x)
May be applied in-place; input and output arrays may be the same.
a3
- filter coefficients.y
- output array.x
- input array.public void applyInverseTranspose(LocalCausalFilter.A3 a3, float[][][] y, float[][][] x)
The inverse transpose cannot be applied in-place; input and output arrays cannot be the same array.
a3
- filter coefficients.y
- output array.x
- input array.