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DOC specgram() documentation now in numpy style
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Exhor authored and NelleV committed Sep 15, 2016
1 parent 5f553bc commit bd2545e
Showing 1 changed file with 47 additions and 60 deletions.
107 changes: 47 additions & 60 deletions lib/matplotlib/mlab.py
Expand Up @@ -1239,78 +1239,65 @@ def specgram(x, NFFT=None, Fs=None, detrend=None, window=None,
"""
Compute a spectrogram.
Call signature::
specgram(x, NFFT=256, Fs=2,detrend=mlab.detrend_none,
window=mlab.window_hanning, noverlap=128,
cmap=None, xextent=None, pad_to=None, sides='default',
scale_by_freq=None, mode='default')
Compute and plot a spectrogram of data in *x*. Data are split into
*NFFT* length segments and the spectrum of each section is
computed. The windowing function *window* is applied to each
Compute and plot a spectrogram of data in x. Data are split into
NFFT length segments and the spectrum of each section is
computed. The windowing function window is applied to each
segment, and the amount of overlap of each segment is
specified with *noverlap*.
specified with noverlap.
*x*: 1-D array or sequence
Array or sequence containing the data
Parameters
----------
x : array_like
1-D array or sequence.
%(Spectral)s
%(PSD)s
*mode*: [ 'default' | 'psd' | 'complex' | 'magnitude'
'angle' | 'phase' ]
What sort of spectrum to use. Default is 'psd'. which takes the
power spectral density. 'complex' returns the complex-valued
frequency spectrum. 'magnitude' returns the magnitude spectrum.
'angle' returns the phase spectrum without unwrapping. 'phase'
returns the phase spectrum with unwrapping.
*noverlap*: integer
The number of points of overlap between blocks. The default value
is 128.
Returns the tuple (*spectrum*, *freqs*, *t*):
*spectrum*: 2-D array
columns are the periodograms of successive segments
*freqs*: 1-D array
The frequencies corresponding to the rows in *spectrum*
noverlap : int, optional
The number of points of overlap between blocks. The default
value is 128.
mode : str, optional
What sort of spectrum to use, default is 'psd'.
'psd'
Returns the power spectral density.
'complex'
Returns the complex-valued frequency spectrum.
'magnitude'
Returns the magnitude spectrum.
'angle'
Returns the phase spectrum without unwrapping.
'phase'
Returns the phase spectrum with unwrapping.
*t*: 1-D array
The times corresponding to midpoints of segments (i.e the columns
in *spectrum*).
.. note::
*detrend* and *scale_by_freq* only apply when *mode* is set to
'psd'
.. seealso::
:func:`psd`
:func:`psd` differs in the default overlap; in returning
the mean of the segment periodograms; and in not returning
times.
Returns
-------
spectrum: array_like
2-D array, columns are the periodograms of successive segments.
:func:`complex_spectrum`
A single spectrum, similar to having a single segment when
*mode* is 'complex'.
freqs: array_like
1-D array, frequencies corresponding to the rows in *spectrum*.
:func:`magnitude_spectrum`
A single spectrum, similar to having a single segment when
*mode* is 'magnitude'.
t : array_like
1-D array, the times corresponding to midpoints of segments
(i.e the columns in *spectrum*).
:func:`angle_spectrum`
A single spectrum, similar to having a single segment when
*mode* is 'angle'.
See Also
--------
psd : differs in the default overlap; in returning the mean of the segment periodograms; and in not returning times.
complex_spectrum : A single spectrum, similar to having a single segment when mode is 'complex'.
magnitude_spectrum : A single spectrum, similar to having a single segment when mode is 'magnitude'.
angle_spectrum : A single spectrum, similar to having a single segment when mode is 'angle'.
phase_spectrum : A single spectrum, similar to having a single segment when mode is 'phase'.
:func:`phase_spectrum`
A single spectrum, similar to having a single segment when
*mode* is 'phase'.
Notes
-----
detrend and scale_by_freq only apply when *mode* is set to 'psd'.
"""
if noverlap is None:
noverlap = 128
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