matplotlib.pyplot.magnitude_spectrum — Matplotlib 3.10.3 documentation (original) (raw)

matplotlib.pyplot.magnitude_spectrum(x, *, Fs=None, Fc=None, window=None, pad_to=None, sides=None, scale=None, data=None, **kwargs)[source]#

Plot the magnitude spectrum.

Compute the magnitude spectrum of x. Data is padded to a length of pad_to and the windowing function window is applied to the signal.

Parameters:

x1-D array or sequence

Array or sequence containing the data.

Fsfloat, default: 2

The sampling frequency (samples per time unit). It is used to calculate the Fourier frequencies, freqs, in cycles per time unit.

windowcallable or ndarray, default: window_hanning

A function or a vector of length NFFT. To create window vectors seewindow_hanning, window_none, numpy.blackman, numpy.hamming,numpy.bartlett, scipy.signal, scipy.signal.get_window, etc. If a function is passed as the argument, it must take a data segment as an argument and return the windowed version of the segment.

sides{'default', 'onesided', 'twosided'}, optional

Which sides of the spectrum to return. 'default' is one-sided for real data and two-sided for complex data. 'onesided' forces the return of a one-sided spectrum, while 'twosided' forces two-sided.

pad_toint, optional

The number of points to which the data segment is padded when performing the FFT. While not increasing the actual resolution of the spectrum (the minimum distance between resolvable peaks), this can give more points in the plot, allowing for more detail. This corresponds to the n parameter in the call to fft. The default is None, which sets _pad_to_equal to the length of the input signal (i.e. no padding).

scale{'default', 'linear', 'dB'}

The scaling of the values in the spec. 'linear' is no scaling. 'dB' returns the values in dB scale, i.e., the dB amplitude (20 * log10). 'default' is 'linear'.

Fcint, default: 0

The center frequency of x, which offsets the x extents of the plot to reflect the frequency range used when a signal is acquired and then filtered and downsampled to baseband.

Returns:

spectrum1-D array

The values for the magnitude spectrum before scaling (real valued).

freqs1-D array

The frequencies corresponding to the elements in spectrum.

lineLine2D

The line created by this function.

Other Parameters:

dataindexable object, optional

If given, the following parameters also accept a string s, which is interpreted as data[s] if s is a key in data:

**kwargs

Keyword arguments control the Line2D properties: