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""" |
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======================================= |
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Signal processing (:mod:`scipy.signal`) |
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======================================= |
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Convolution |
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=========== |
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.. autosummary:: |
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:toctree: generated/ |
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convolve -- N-D convolution. |
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correlate -- N-D correlation. |
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fftconvolve -- N-D convolution using the FFT. |
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oaconvolve -- N-D convolution using the overlap-add method. |
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convolve2d -- 2-D convolution (more options). |
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correlate2d -- 2-D correlation (more options). |
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sepfir2d -- Convolve with a 2-D separable FIR filter. |
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choose_conv_method -- Chooses faster of FFT and direct convolution methods. |
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correlation_lags -- Determines lag indices for 1D cross-correlation. |
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B-splines |
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========= |
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.. autosummary:: |
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:toctree: generated/ |
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gauss_spline -- Gaussian approximation to the B-spline basis function. |
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cspline1d -- Coefficients for 1-D cubic (3rd order) B-spline. |
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qspline1d -- Coefficients for 1-D quadratic (2nd order) B-spline. |
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cspline2d -- Coefficients for 2-D cubic (3rd order) B-spline. |
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qspline2d -- Coefficients for 2-D quadratic (2nd order) B-spline. |
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cspline1d_eval -- Evaluate a cubic spline at the given points. |
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qspline1d_eval -- Evaluate a quadratic spline at the given points. |
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spline_filter -- Smoothing spline (cubic) filtering of a rank-2 array. |
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Filtering |
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========= |
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.. autosummary:: |
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:toctree: generated/ |
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order_filter -- N-D order filter. |
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medfilt -- N-D median filter. |
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medfilt2d -- 2-D median filter (faster). |
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wiener -- N-D Wiener filter. |
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symiirorder1 -- 2nd-order IIR filter (cascade of first-order systems). |
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symiirorder2 -- 4th-order IIR filter (cascade of second-order systems). |
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lfilter -- 1-D FIR and IIR digital linear filtering. |
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lfiltic -- Construct initial conditions for `lfilter`. |
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lfilter_zi -- Compute an initial state zi for the lfilter function that |
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-- corresponds to the steady state of the step response. |
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filtfilt -- A forward-backward filter. |
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savgol_filter -- Filter a signal using the Savitzky-Golay filter. |
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deconvolve -- 1-D deconvolution using lfilter. |
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sosfilt -- 1-D IIR digital linear filtering using |
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-- a second-order sections filter representation. |
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sosfilt_zi -- Compute an initial state zi for the sosfilt function that |
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-- corresponds to the steady state of the step response. |
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sosfiltfilt -- A forward-backward filter for second-order sections. |
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hilbert -- Compute 1-D analytic signal, using the Hilbert transform. |
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hilbert2 -- Compute 2-D analytic signal, using the Hilbert transform. |
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envelope -- Compute the envelope of a real- or complex-valued signal. |
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decimate -- Downsample a signal. |
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detrend -- Remove linear and/or constant trends from data. |
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resample -- Resample using Fourier method. |
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resample_poly -- Resample using polyphase filtering method. |
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upfirdn -- Upsample, apply FIR filter, downsample. |
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Filter design |
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============= |
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.. autosummary:: |
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:toctree: generated/ |
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bilinear -- Digital filter from an analog filter using |
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-- the bilinear transform. |
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bilinear_zpk -- Digital filter from an analog filter using |
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-- the bilinear transform. |
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findfreqs -- Find array of frequencies for computing filter response. |
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firls -- FIR filter design using least-squares error minimization. |
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firwin -- Windowed FIR filter design, with frequency response |
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-- defined as pass and stop bands. |
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firwin2 -- Windowed FIR filter design, with arbitrary frequency |
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-- response. |
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freqs -- Analog filter frequency response from TF coefficients. |
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freqs_zpk -- Analog filter frequency response from ZPK coefficients. |
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freqz -- Digital filter frequency response from TF coefficients. |
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freqz_sos -- Digital filter frequency response for SOS format filter. |
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freqz_zpk -- Digital filter frequency response from ZPK coefficients. |
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gammatone -- FIR and IIR gammatone filter design. |
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group_delay -- Digital filter group delay. |
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iirdesign -- IIR filter design given bands and gains. |
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iirfilter -- IIR filter design given order and critical frequencies. |
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kaiser_atten -- Compute the attenuation of a Kaiser FIR filter, given |
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-- the number of taps and the transition width at |
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-- discontinuities in the frequency response. |
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kaiser_beta -- Compute the Kaiser parameter beta, given the desired |
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-- FIR filter attenuation. |
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kaiserord -- Design a Kaiser window to limit ripple and width of |
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-- transition region. |
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minimum_phase -- Convert a linear phase FIR filter to minimum phase. |
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savgol_coeffs -- Compute the FIR filter coefficients for a Savitzky-Golay |
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-- filter. |
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remez -- Optimal FIR filter design. |
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unique_roots -- Unique roots and their multiplicities. |
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residue -- Partial fraction expansion of b(s) / a(s). |
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residuez -- Partial fraction expansion of b(z) / a(z). |
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invres -- Inverse partial fraction expansion for analog filter. |
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invresz -- Inverse partial fraction expansion for digital filter. |
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BadCoefficients -- Warning on badly conditioned filter coefficients. |
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Lower-level filter design functions: |
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.. autosummary:: |
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:toctree: generated/ |
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abcd_normalize -- Check state-space matrices and ensure they are rank-2. |
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band_stop_obj -- Band Stop Objective Function for order minimization. |
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besselap -- Return (z,p,k) for analog prototype of Bessel filter. |
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buttap -- Return (z,p,k) for analog prototype of Butterworth filter. |
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cheb1ap -- Return (z,p,k) for type I Chebyshev filter. |
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cheb2ap -- Return (z,p,k) for type II Chebyshev filter. |
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ellipap -- Return (z,p,k) for analog prototype of elliptic filter. |
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lp2bp -- Transform a lowpass filter prototype to a bandpass filter. |
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lp2bp_zpk -- Transform a lowpass filter prototype to a bandpass filter. |
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lp2bs -- Transform a lowpass filter prototype to a bandstop filter. |
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lp2bs_zpk -- Transform a lowpass filter prototype to a bandstop filter. |
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lp2hp -- Transform a lowpass filter prototype to a highpass filter. |
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lp2hp_zpk -- Transform a lowpass filter prototype to a highpass filter. |
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lp2lp -- Transform a lowpass filter prototype to a lowpass filter. |
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lp2lp_zpk -- Transform a lowpass filter prototype to a lowpass filter. |
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normalize -- Normalize polynomial representation of a transfer function. |
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Matlab-style IIR filter design |
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============================== |
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.. autosummary:: |
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:toctree: generated/ |
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butter -- Butterworth |
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buttord |
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cheby1 -- Chebyshev Type I |
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cheb1ord |
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cheby2 -- Chebyshev Type II |
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cheb2ord |
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ellip -- Elliptic (Cauer) |
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ellipord |
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bessel -- Bessel (no order selection available -- try butterod) |
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iirnotch -- Design second-order IIR notch digital filter. |
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iirpeak -- Design second-order IIR peak (resonant) digital filter. |
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iircomb -- Design IIR comb filter. |
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Continuous-time linear systems |
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============================== |
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.. autosummary:: |
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:toctree: generated/ |
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lti -- Continuous-time linear time invariant system base class. |
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StateSpace -- Linear time invariant system in state space form. |
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TransferFunction -- Linear time invariant system in transfer function form. |
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ZerosPolesGain -- Linear time invariant system in zeros, poles, gain form. |
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lsim -- Continuous-time simulation of output to linear system. |
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impulse -- Impulse response of linear, time-invariant (LTI) system. |
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step -- Step response of continuous-time LTI system. |
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freqresp -- Frequency response of a continuous-time LTI system. |
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bode -- Bode magnitude and phase data (continuous-time LTI). |
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Discrete-time linear systems |
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============================ |
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.. autosummary:: |
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:toctree: generated/ |
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dlti -- Discrete-time linear time invariant system base class. |
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StateSpace -- Linear time invariant system in state space form. |
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TransferFunction -- Linear time invariant system in transfer function form. |
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ZerosPolesGain -- Linear time invariant system in zeros, poles, gain form. |
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dlsim -- Simulation of output to a discrete-time linear system. |
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dimpulse -- Impulse response of a discrete-time LTI system. |
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dstep -- Step response of a discrete-time LTI system. |
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dfreqresp -- Frequency response of a discrete-time LTI system. |
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dbode -- Bode magnitude and phase data (discrete-time LTI). |
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LTI representations |
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=================== |
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.. autosummary:: |
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:toctree: generated/ |
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tf2zpk -- Transfer function to zero-pole-gain. |
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tf2sos -- Transfer function to second-order sections. |
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tf2ss -- Transfer function to state-space. |
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zpk2tf -- Zero-pole-gain to transfer function. |
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zpk2sos -- Zero-pole-gain to second-order sections. |
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zpk2ss -- Zero-pole-gain to state-space. |
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ss2tf -- State-pace to transfer function. |
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ss2zpk -- State-space to pole-zero-gain. |
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sos2zpk -- Second-order sections to zero-pole-gain. |
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sos2tf -- Second-order sections to transfer function. |
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cont2discrete -- Continuous-time to discrete-time LTI conversion. |
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place_poles -- Pole placement. |
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Waveforms |
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========= |
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.. autosummary:: |
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:toctree: generated/ |
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chirp -- Frequency swept cosine signal, with several freq functions. |
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gausspulse -- Gaussian modulated sinusoid. |
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max_len_seq -- Maximum length sequence. |
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sawtooth -- Periodic sawtooth. |
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square -- Square wave. |
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sweep_poly -- Frequency swept cosine signal; freq is arbitrary polynomial. |
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unit_impulse -- Discrete unit impulse. |
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Window functions |
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================ |
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For window functions, see the `scipy.signal.windows` namespace. |
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In the `scipy.signal` namespace, there is a convenience function to |
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obtain these windows by name: |
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.. autosummary:: |
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:toctree: generated/ |
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get_window -- Return a window of a given length and type. |
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Peak finding |
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============ |
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.. autosummary:: |
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:toctree: generated/ |
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argrelmin -- Calculate the relative minima of data. |
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argrelmax -- Calculate the relative maxima of data. |
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argrelextrema -- Calculate the relative extrema of data. |
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find_peaks -- Find a subset of peaks inside a signal. |
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find_peaks_cwt -- Find peaks in a 1-D array with wavelet transformation. |
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peak_prominences -- Calculate the prominence of each peak in a signal. |
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peak_widths -- Calculate the width of each peak in a signal. |
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Spectral analysis |
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================= |
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.. autosummary:: |
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:toctree: generated/ |
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periodogram -- Compute a (modified) periodogram. |
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welch -- Compute a periodogram using Welch's method. |
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csd -- Compute the cross spectral density, using Welch's method. |
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coherence -- Compute the magnitude squared coherence, using Welch's method. |
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spectrogram -- Compute the spectrogram (legacy). |
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lombscargle -- Computes the Lomb-Scargle periodogram. |
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vectorstrength -- Computes the vector strength. |
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ShortTimeFFT -- Interface for calculating the \ |
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:ref:`Short Time Fourier Transform <tutorial_stft>` and \ |
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its inverse. |
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stft -- Compute the Short Time Fourier Transform (legacy). |
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istft -- Compute the Inverse Short Time Fourier Transform (legacy). |
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check_COLA -- Check the COLA constraint for iSTFT reconstruction. |
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check_NOLA -- Check the NOLA constraint for iSTFT reconstruction. |
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Chirp Z-transform and Zoom FFT |
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============================================ |
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.. autosummary:: |
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:toctree: generated/ |
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czt - Chirp z-transform convenience function |
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zoom_fft - Zoom FFT convenience function |
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CZT - Chirp z-transform function generator |
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ZoomFFT - Zoom FFT function generator |
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czt_points - Output the z-plane points sampled by a chirp z-transform |
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The functions are simpler to use than the classes, but are less efficient when |
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using the same transform on many arrays of the same length, since they |
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repeatedly generate the same chirp signal with every call. In these cases, |
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use the classes to create a reusable function instead. |
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""" |
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from . import _sigtools, windows |
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from ._waveforms import * |
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from ._max_len_seq import max_len_seq |
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from ._upfirdn import upfirdn |
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from ._spline import ( |
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sepfir2d |
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) |
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from ._spline_filters import * |
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from ._filter_design import * |
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from ._fir_filter_design import * |
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from ._ltisys import * |
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from ._lti_conversion import * |
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from ._signaltools import * |
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from ._savitzky_golay import savgol_coeffs, savgol_filter |
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from ._spectral_py import * |
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from ._short_time_fft import * |
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from ._peak_finding import * |
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from ._czt import * |
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from .windows import get_window |
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from . import ( |
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bsplines, filter_design, fir_filter_design, lti_conversion, ltisys, |
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spectral, signaltools, waveforms, wavelets, spline |
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) |
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__all__ = [ |
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s for s in dir() if not s.startswith("_") |
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] |
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from scipy._lib._testutils import PytestTester |
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test = PytestTester(__name__) |
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del PytestTester |
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