DSP SPL Directory

 

The DSP directory contains SPL functions related to digital signal processing (DSP) and Fourier transforms. The directory includes the following SPL files:

 

ACORR

Calculates the auto-correlation using the convolution method.

ACOV

Calculates the auto-covariance using the convolution method.

AMPSPEC

Calculates normalized complex FFT

AVGFILT

Filters a series using the average of the N neighboring points.

BESTPOW2

Finds the power of 2 greater than or equal to the input value or length of the input series.

BILINEAR

Performs a bilinear transformation with optional frequency prewarping.

BITQUANT

Quantizes an input series to 2^bits levels.

BITSCALE

Converts raw AD counts to scaled engineering values.

CCEPS

Calculates the complex cepstrum.

CLOGMAG

Evaluates the log magnitude of Cascade form coefficients.

COVM

Calculates the covariance matrix of an array.

DCT

Calculates the Discrete Cosine Transform.

DECONV

Performs direct deconvolution in the time domain.

DEMEAN

Removes the mean (or DC value) from a series

DEMODFM

Demodulates an FM waveform using the Hilbert Transform.

EFFBIT

Calculate the number of effective bits possible at a given frequency for a quantizing device.

ENDFLIP

Pads the ends of a series with endpoint reflections.

FACORR

Calculates the auto-correlation using the FFT method.

FACOV

Calculates the auto-covariance using the FFT method.

FCONV

Performs convolution using the FFT method.

FDECONV

Performs deconvolution using the FFT method.

FFTSHIFT

Shifts a 1D or 2D FFT so the 0 frequency is the midpoint.

FILTEQ

Evaluates a Linear Constant Coefficient Difference Equation.

FIRSAMP

Designs an arbitrary FIR filter using frequency sampling.

FREQS

Evaluates the frequency response of a continuous system.

FREQSAMP

Designs a FIR filter from a given magnitude response using the frequency sampling method.

FREQZ

Evaluates the frequency response of a discrete system.

FXCORR

Calculates the cross correlation using the FFT method.

FXCOV

Calculates the covariance using the FFT method.

FZINTERP

Interpolates a series by a factor using FFT zero insertion.

GRPDELAY

Calculates the group delay of a Z transform.

HAMMING

Multiplies a series with a Hamming window.

HANNING

Multiplies a series with a Hanning window.

HILB

Calculates a simple Hilbert transform of a real series.

ICCEPS

Calculates the complex cepstrum.

IDCT

Calculates the Inverse Discrete Cosine Transform.

IMPZ

Calculates the impulse response of a Z transform.

INVFREQS

Calculates analog filter coefficients from a complex frequency response.

INVFREQZ

Calculates digital filter coefficients from a complex frequency response.

INVPSD

Construct a time series from a PSD.

KAISER

Multiplies a series with a Kaiser window.

LINSCALE

Linearly rescales an input series.

LOG2

Returns Log base 2 of the input.

MAGSPEC

Calculates the magnitude of the complex amplitude spectrum

MODFM

Frequency modulate an input series.

NEXTPOW2

Determines the exponent for the next power of 2 greater than or equal to the input value.

NFFT

Calculates an N point FFT via zero padding or time aliasing.

NSPECTRUM

Calculates an N point spectrum via zero padding or time aliasing.

OASFILT

Filters data using the overlap and save method.

PADFILT

FIR filtering with optional endpoint padding.

PHASESPEC

Calculates the phase of the complex amplitude spectrum

POLY

Calculates coefficients of the characteristic polynomial.

POLYSTAB

Stabilizes a denominator polynomial by root reflection.

QUANTIZE

Quantizes an input series to N levels.

RCEPS

Calculates the real cepstrum.

REMOVENA

Removes the NAVALUEs from a series or array.

RESCALE

Linearly rescales an input series.

RESIDUE

Finds the partial fraction expansion of a rational polynomial.

RESIDUEZ

Finds the partial fraction expansion of a Z transform.

SFREQ

Evaluates the frequency response of a continuous system in Hertz.

SHP

Emulates a single pole analog high pass filter.

SLP

Emulates a single pole analog low pass filter.

SONOGRAM

Calculates the 2D Spectrogram as a B&W image.

SPECGRAM

Calculates the 2D Spectrogram as an image.

STARMS

Calculates the short time averaged RMS series.

TF2SS

Calculates the state-space representation

WINFUNC

Multiplies a series with a spectral window.

XCORR

Calculates the cross correlation using the convolution method.

XCOV

Calculates the cross covariance using direct convolution.

ZEROFLIP

Pads the ends of a series with endpoint reflections about 0.0.

ZFREQ

Evaluates the frequency response of a Z transform.

ZINTERP

Interpolates a series to a new sample rate by FFT zero insertion.

ZPFCOEF

Designs a digital filter from a set of analog zeros and poles (S domain).

ZPLANE

Displays a Pole-Zero plot of a Z transform.