Changeset fc117d0 for python/demos/demo_spectrogram.py

Timestamp:

Feb 11, 2013, 11:06:28 AM (11 years ago)

Author:

Paul Brossier <piem@piem.org>

Branches:

feature/autosink, feature/cnn, feature/cnn_org, feature/constantq, feature/crepe, feature/crepe_org, feature/pitchshift, feature/pydocstrings, feature/timestretch, fix/ffmpeg5, master, pitchshift, sampler, timestretch, yinfft+

Children:

050a8f3

Parents:

5314432 (diff), 88fc249 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

merge from develop

File:

• python/demos/demo_spectrogram.py (moved) (moved from interfaces/python/demo_spectrogram.py) (2 diffs)

python/demos/demo_spectrogram.py

@@ -1 @@
-#! /usr/bin/python
+#! /usr/bin/env python
 
 import sys
@@ -23 +23 @@
 
   # plotting
-  imshow(log10(specgram.T), origin = 'bottom', aspect = 'auto', cmap=cm.gray_r)
+  imshow(log10(specgram.T + .001), origin = 'bottom', aspect = 'auto', cmap=cm.gray_r)
   axis([0, len(specgram), 0, len(specgram[0])])
-  ylabel('Frequency (Hz)')
-  xlabel('Time (s)')
   # show axes in Hz and seconds
   time_step = hop_s / float(samplerate)
   total_time = len(specgram) * time_step
-  ticks = 10
-  xticks( arange(ticks) / float(ticks) * len(specgram),
-      [x * total_time / float(ticks) for x in range(ticks) ] )
-  yticks( arange(ticks) / float(ticks) * len(specgram[0]),
-      [x * samplerate / 2. / float(ticks) for x in range(ticks) ] )
+  print "total time: %0.2fs" % total_time,
+  print ", samplerate: %.2fkHz" % (samplerate / 1000.)
+  n_xticks = 10
+  n_yticks = 10
+
+  def get_rounded_ticks( top_pos, step, n_ticks ):
+      top_label = top_pos * step
+      # get the first label
+      ticks_first_label = top_pos * step / n_ticks
+      # round to the closest .1
+      ticks_first_label = round ( ticks_first_label * 10. ) / 10.
+      # compute all labels from the first rounded one
+      ticks_labels = [ ticks_first_label * n for n in range(n_ticks) ] + [ top_label ]
+      # get the corresponding positions
+      ticks_positions = [ ticks_labels[n] / step for n in range(n_ticks) ] + [ top_pos ]
+      # convert to string
+      ticks_labels = [  "%.1f" % x for x in ticks_labels ]
+      # return position, label tuple to use with x/yticks
+      return ticks_positions, ticks_labels
+
+  # apply to the axis
+  xticks( *get_rounded_ticks ( len(specgram), time_step, n_xticks ) )
+  yticks( *get_rounded_ticks ( len(specgram[0]), (samplerate / 2. / 1000.) / len(specgram[0]), n_yticks ) )
+  ylabel('Frequency (kHz)')
+  xlabel('Time (s)')
 
 if __name__ == '__main__':