Signal Processing Cheat Sheet

needs import breeze.signal._
Note: many of these functions have extensive optional parameters in breeze. See the ScalaDoc for a description of each parameter.

Basic Operations

| Operation | Breeze | Numpy | Matlab | | ---- | ---- | ---- | ---- | ---- | ---- | | Convolve | convolve[Input, KernelType, Output] | conv(u,v) | conv(u,v) | | Correlate | correlate[Input, KernelType, Output] | xcorr(u,v) | xcorr(u,v)| these Breeze functions will use fft convolution by default for floating point DenseMatrixes and DenseVectors. For Int and Long DV/DMs, you can specify fft convolution by specifying the optional argument optMethod = OptMethod.FFT

Transforms

| Operation | Breeze | Numpy | Matlab | | ---- | ---- | ---- | ---- | ---- | ---- | | 1D Fourier transform | fourierTr( data: Array[Complex ) | fft( a ) | fft( a ) | | 1D Inverse Fourier transform | iFourierTr(data: Array[Complex]) | ifft( a ) | ifft( a ) | | 2D Fourier Transform | fourierTr2C(data: Array[Array[Complex]]) | fft2( a ) | fft2( a ) | | 2D Inverse Fourier Transform | iFourierTr( data: Array[Array[Complex]] ) | ifft2( a ) | ifft2( a ) |

Convenience Functions for DFT

| Operation | Breeze | Numpy | Matlab | | ---- | ---- | ---- | ---- | ---- | ---- | | Fourier frequencies | fourierFreq( n, dt = (timestep) ) or fourierFreq( n, fs = (sample freq) ) | fftfreq(n, dt) | --- | | Fourier shift | fourierShift( data: Array[Double] ) | fftshift( a ) | fftshift( a ) | | (inverse) | iFourierShift( data: Array[Double] ) | ifftshift( a ) | ifftshift( a ) |

Filtering

| Operation | Breeze | Numpy | Matlab | | ---- | ---- | ---- | ---- | ---- | ---- | | Filter | filter( data: Input, kernel: Kernel, overhang: OptOverhang = OptOverhang.PreserveLength, padding: OptPadding = OptPadding.Zero ) | --- | --- | | Bandpass Filter | filterBP( data: Array[Double], omegaLow: Double, omegaHigh: Double, sampleRate: Double, taps = 512 ) | --- | --- | | Bandstop Filter | filterBS( data: Array[Double], omegaLow: Double, omegaHigh: Double, sampleRate: Double, taps = 512 ) | --- | --- | | Lowpass Filter | filterLP( data: Array[Double], omega: Double, sampleRate: Double, taps = 512 ) | --- | --- | | Highpass Filter | filterHP( data: Array[Double], omega: Double, sampleRate: Double, taps = 512 ) | --- | --- | | Median Filter | filterMedian( data: DenseVector[Input], windowLength: Int, overhang: OptOverhang = OptOverhang.PreserveLength ) | --- | --- |