SF.net SVN: matplotlib:[6390] trunk/matplotlib

[<ry...@us...>]

Revision: 6390
          http://matplotlib.svn.sourceforge.net/matplotlib/?rev=6390&view=rev
Author:   ryanmay
Date:     2008-11-11 17:56:07 +0000 (Tue, 11 Nov 2008)

Log Message:
-----------
Update the axes.psd() method to reflect the new options available in mlab.psd.  Add an example to show how the options change things.

Modified Paths:
--------------
    trunk/matplotlib/CHANGELOG
    trunk/matplotlib/lib/matplotlib/axes.py

Added Paths:
-----------
    trunk/matplotlib/examples/pylab_examples/psd_demo2.py

Modified: trunk/matplotlib/CHANGELOG
===================================================================
--- trunk/matplotlib/CHANGELOG	2008-11-11 16:30:03 UTC (rev 6389)
+++ trunk/matplotlib/CHANGELOG	2008-11-11 17:56:07 UTC (rev 6390)
@@ -1,3 +1,7 @@
+2008-11-11 Update the axes.psd() method to reflect the new options
+           available in mlab.psd.  Add an example to show how the
+           options change things. - RM
+
 2008-11-11 Add 'pad_to' and 'sides' parameters to mlab.psd() to
            allow controlling of zero padding and returning of
            negative frequency components, respecitively.  These are

Added: trunk/matplotlib/examples/pylab_examples/psd_demo2.py
===================================================================
--- trunk/matplotlib/examples/pylab_examples/psd_demo2.py	                        (rev 0)
+++ trunk/matplotlib/examples/pylab_examples/psd_demo2.py	2008-11-11 17:56:07 UTC (rev 6390)
@@ -0,0 +1,39 @@
+#This example shows the effects of some of the different PSD parameters
+import numpy as np
+import matplotlib.pyplot as plt
+
+dt = np.pi / 100.
+fs = 1. / dt
+t = np.arange(0, 8, dt)
+y = 10. * np.sin(2 * np.pi * 4 * t) + 5. * np.sin(2 * np.pi * 4.25 * t)
+y = y + np.random.randn(*t.shape)
+
+#Plot the raw time series
+fig = plt.figure()
+ax = fig.add_subplot(2, 1, 1)
+ax.plot(t, y)
+
+#Plot the PSD with different amounts of zero padding. This uses the entire
+#time series at once
+ax2 = fig.add_subplot(2, 3, 4)
+ax2.psd(y, NFFT=len(t), pad_to=len(t), Fs=fs)
+ax2.psd(y, NFFT=len(t), pad_to=len(t)*2, Fs=fs)
+ax2.psd(y, NFFT=len(t), pad_to=len(t)*4, Fs=fs)
+plt.title('Effect of zero padding')
+
+#Plot the PSD with different block sizes, Zero pad to the length of the orignal
+#data sequence.
+ax3 = fig.add_subplot(2, 3, 5, sharex=ax2, sharey=ax2)
+ax3.psd(y, NFFT=len(t), pad_to=len(t), Fs=fs)
+ax3.psd(y, NFFT=len(t)//2, pad_to=len(t), Fs=fs)
+ax3.psd(y, NFFT=len(t)//4, pad_to=len(t), Fs=fs)
+plt.title('Effect of block size')
+
+#Plot the PSD with different amounts of overlap between blocks
+ax4 = fig.add_subplot(2, 3, 6, sharex=ax2, sharey=ax2)
+ax4.psd(y,NFFT=len(t)//2, pad_to=len(t), noverlap=0, Fs=fs)
+ax4.psd(y,NFFT=len(t)//2, pad_to=len(t), noverlap=int(0.05*len(t)/2.), Fs=fs)
+ax4.psd(y,NFFT=len(t)//2, pad_to=len(t), noverlap=int(0.2*len(t)/2.), Fs=fs)
+plt.title('Effect of overlap')
+
+plt.show()

Modified: trunk/matplotlib/lib/matplotlib/axes.py
===================================================================
--- trunk/matplotlib/lib/matplotlib/axes.py	2008-11-11 16:30:03 UTC (rev 6389)
+++ trunk/matplotlib/lib/matplotlib/axes.py	2008-11-11 17:56:07 UTC (rev 6390)
@@ -6525,7 +6525,8 @@
     hist.__doc__ = cbook.dedent(hist.__doc__) % martist.kwdocd
 
     def psd(self, x, NFFT=256, Fs=2, Fc=0, detrend=mlab.detrend_none,
-            window=mlab.window_hanning, noverlap=0, **kwargs):
+            window=mlab.window_hanning, noverlap=0, pad_to=None,
+            sides='default', **kwargs):
         """
         call signature::
 
@@ -6595,7 +6596,8 @@
         .. plot:: mpl_examples/pylab_examples/psd_demo.py
         """
         if not self._hold: self.cla()
-        pxx, freqs = mlab.psd(x, NFFT, Fs, detrend, window, noverlap)
+        pxx, freqs = mlab.psd(x, NFFT, Fs, detrend, window, noverlap, pad_to,
+            sides)
         pxx.shape = len(freqs),
         freqs += Fc
 


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