scidart library

Functions

arrayBesselI0(Array a) Array
Return modified Bessel function of order 0 for each element of Array. a : Array Returns [...]
besselI0(double x) → double
Return modified Bessel function of order 0 for a number. x : double Returns [...]
blackman(int M, { bool sym: true }) Array
Return a Blackman window. The Blackman window is a taper formed by using the first three terms of a summation of cosines. It was designed to have close to the minimal leakage possible. It is close to optimal, only slightly worse than a Kaiser window. Parameters [...]
blackmanharris(int M, { bool sym: true }) Array
Return a minimum 4-term Blackman-Harris window. Parameters [...]
convolution(Array input, Array kernel, { dynamic fast: false }) Array
Compute the 1D convolution of 2 signals input : input signal kernel : kernel signal that will convolve with input fast : optional parameter default false, if true, compute convolution using FFT if false (default), compute convolution using numerical definition [...]
convolutionCircularComplex(ArrayComplex input, ArrayComplex kernel, { dynamic keepLength: false }) ArrayComplex
Computes the circular convolution of the given complex vectors. Each vector's length must be the same. input : input signal kernel : kernel periodic signal keepLength : the output length is the same of the input, default is false References [...]
convolutionComplex(ArrayComplex input, ArrayComplex kernel) ArrayComplex
Compute the 1D convolution of 2 signals and return a ComplexArray input : input signal ArrayComplex kernel : kernel signal that will convolve with input ArrayComplex References [...]
dbfft(Array x, double fs, { String window, double ref }) → List
Calculate spectrum in dB scale x : input signal fs : sampling frequency window : vector containing window samples (same length as x). If not provided, then rectangular window is used by default. [...]
fft(ArrayComplex x, { int n, bool normalization: false }) ArrayComplex
Compute the one-dimensional discrete Fourier Transform. x : A ArrayComplex with the input n : optional Length of the transformed axis of the output. If n is smaller than the length of the input, the input is cropped. If it is larger, the input is padded with zeros. If n is not given, the length of the input is used. normalization : optional default false Compute the FFT normalization wich is: fft(x)/n [...]
fftFreq(int n, { double d: 1.0, bool realFrequenciesOnly: false }) Array
Return the Discrete Fourier Transform sample frequencies. The returned float array f contains the frequency bin centers in cycles per unit of the sample spacing (with zero at the start). For instance, if the sample spacing is in seconds, then the frequency unit is cycles/second. Given a window length n and a sample spacing d:: f = 0, 1, ..., n/2-1, -n/2, ..., -1 / (dn) if n is even f = 0, 1, ..., (n-1)/2, -(n-1)/2, ..., -1 / (dn) if n is odd Parameters [...]
findPeaks(Array a, { double threshold }) → List
Find the peak of Array a : Array input threshold : optional, only consider peaks greater equal then peaks Return List ix : list of indexes of the peak in the array ax : list of the value of the peaks found References [...]
firwin(int numtaps, Array cutoff, { double width, dynamic window: 'hamming', dynamic pass_zero: true, bool scale: true, double nyq, double fs }) → dynamic
FIR filter design using the window method. This function computes the coefficients of a finite impulse response filter. The filter will have linear phase; it will be Type I if numtaps is odd and Type II if numtaps is even. Type II filters always have zero response at the Nyquist frequency, so a ValueError exception is raised if firwin is called with numtaps even and having a passband whose right end is at the Nyquist frequency. Parameters [...]
flattop(int M, { bool sym: true }) Array
Return a flat top window. Parameters [...]
generalCosine(int M, Array a, { bool sym: true }) Array
Generic weighted sum of cosine terms window Parameters [...]
generalHamming(int M, double alpha, { bool sym: true }) Array
Return a generalized Hamming window. The generalized Hamming window is constructed by multiplying a rectangular window by one period of a cosine function 1_. Parameters [...]
getWindow(dynamic window, int Nx, { bool fftbins: true }) Array
Return a window. Parameters [...]
hamming(int M, { bool sym: true }) Array
Return a Hamming window. The Hamming window is a taper formed by using a raised cosine with non-zero endpoints, optimized to minimize the nearest side lobe. Parameters [...]
hann(int M, { bool sym: true }) Array
Return a Hann window. The Hann window is a taper formed by using a raised cosine or sine-squared with ends that touch zero. Parameters [...]
ifft(ArrayComplex X) ArrayComplex
Compute the one-dimensional inverse discrete Fourier Transform. X A ArrayComplex with the input return A ArrayComplex with IFFT output References [...]
kaiser(int M, double beta, { bool sym: true }) Array
Return a Kaiser window. The Kaiser window is a taper formed by using a Bessel function. Parameters [...]
kaiserAtten(int numtaps, double width) → double
Compute the attenuation of a Kaiser FIR filter. Given the number of taps N and the transition width width, compute the attenuation a in dB, given by Kaiser's formula: a = 2.285 * (N - 1) * pi * width + 7.95 [...]
kaiserBeta(double a) → double
Compute the Kaiser parameter beta, given the attenuation a. Parameters [...]
lfilter(Array b, Array a, Array x) Array
Filter data along one-dimension with an IIR or FIR filter. The filter is a direct form II transposed implementation of the standard difference equation. Parameters [...]
nuttall(int M, { bool sym: true }) Array
Return a minimum 4-term Blackman-Harris window according to Nuttall. This variation is called "Nuttall4c" by Heinzel. 1_ Parameters [...]
rfft(Array x, { dynamic n }) ArrayComplex
Compute the one-dimensional discrete Fourier Transform for a Real input. x A Array with the input n : optional Length of the transformed axis of the output. If n is smaller than the length of the input, the input is cropped. If it is larger, the input is padded with zeros. If n is not given, the length of the input is used. [...]
rifft(ArrayComplex x) Array
Compute the one-dimensional inverse discrete Fourier Transform and return a Real output. X A ArrayComplex with the input return A Array with IFFT output References [...]