Get more time points on x axis of a spectrogram
0
So I've represented a spectrogram for a relatively long video(15 minutes). On the time axis, I've got data points at each 3 minute and 20 seconds.
This is my spectrogram:
I would like to have data point on the x axis for every second. I've tries to modify the function timeTicks from the code, but it doesn't work. As an alternative, I've seen that I could zoom in on my spectrogram, but I can't seem to get it to work.
This is the code:
import matplotlib.pyplot as plt
import scipy.io.wavfile as wavfile
cmap = plt.get_cmap('plasma') # this may fail on older versions of matplotlib
vmin = -40 # hide anything below -40 dB
cmap.set_under(color='k', alpha=None)
rate, frames = wavfile.read("audio_test.wav")
fig, ax = plt.subplots()
pxx, freq, t, cax = ax.specgram(frames[:, 0], # first channel
Fs=rate, # to get frequency axis in Hz
cmap=cmap, vmin=vmin)
cbar = fig.colorbar(cax)
cbar.set_label('Intensity dB')
ax.axis("tight")
# Prettify
import matplotlib
import datetime
ax.set_xlabel('time h:mm:ss')
ax.set_ylabel('frequency kHz')
scale = 1e3 # KHz
ticks = matplotlib.ticker.FuncFormatter(lambda x, pos: '{0:g}'.format(x/scale))
ax.yaxis.set_major_formatter(ticks)
def timeTicks(x, pos):
d = datetime.timedelta(seconds=x)
return str(d)
formatter = matplotlib.ticker.FuncFormatter(timeTicks)
ax.xaxis.set_major_formatter(formatter)
ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))
plt.show()
Edit:
The present spectogram:
python matplotlib spectrogram
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
add a comment |
0
So I've represented a spectrogram for a relatively long video(15 minutes). On the time axis, I've got data points at each 3 minute and 20 seconds.
This is my spectrogram:
I would like to have data point on the x axis for every second. I've tries to modify the function timeTicks from the code, but it doesn't work. As an alternative, I've seen that I could zoom in on my spectrogram, but I can't seem to get it to work.
This is the code:
import matplotlib.pyplot as plt
import scipy.io.wavfile as wavfile
cmap = plt.get_cmap('plasma') # this may fail on older versions of matplotlib
vmin = -40 # hide anything below -40 dB
cmap.set_under(color='k', alpha=None)
rate, frames = wavfile.read("audio_test.wav")
fig, ax = plt.subplots()
pxx, freq, t, cax = ax.specgram(frames[:, 0], # first channel
Fs=rate, # to get frequency axis in Hz
cmap=cmap, vmin=vmin)
cbar = fig.colorbar(cax)
cbar.set_label('Intensity dB')
ax.axis("tight")
# Prettify
import matplotlib
import datetime
ax.set_xlabel('time h:mm:ss')
ax.set_ylabel('frequency kHz')
scale = 1e3 # KHz
ticks = matplotlib.ticker.FuncFormatter(lambda x, pos: '{0:g}'.format(x/scale))
ax.yaxis.set_major_formatter(ticks)
def timeTicks(x, pos):
d = datetime.timedelta(seconds=x)
return str(d)
formatter = matplotlib.ticker.FuncFormatter(timeTicks)
ax.xaxis.set_major_formatter(formatter)
ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))
plt.show()
Edit:
The present spectogram:
python matplotlib spectrogram
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
set_major_formatteronly controls how each tick label is written. To control where the ticks are, you need toset_major_locatorwith a tick locator frommatplotlib.dates.
– Joooeey
Nov 23 '18 at 0:08
and if you don't want labels on all your ticks, useset_minor_locator. A label on every second would be too much.
– Joooeey
Nov 23 '18 at 0:09
Thank you for your response @Joooeey! Can't seem to get it done... I've added this line of code: "ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))". I have a weird value after the seconds on the x value. Something like ".001415" and I don't know how to get rid of it. I'll attach a new picture with the present spectrogram.
– PyRar
Nov 23 '18 at 5:36
Try:from matplotlib import datesand thenax.xaxis.set_major_locator(dates.MinuteLocator(interval=2))andax.xaxis.set_minor_locator(dates.SecondLocator()).
– Joooeey
Nov 23 '18 at 17:00
I don't know what the issue with the IndexLocator is, but you can hide the problem by not displaying fractions of a second:ax.xaxis.set_major_formatter(dates.DateFormatter('%H:%M:%S')
– Joooeey
Nov 23 '18 at 17:06
add a comment |
0
0
0
So I've represented a spectrogram for a relatively long video(15 minutes). On the time axis, I've got data points at each 3 minute and 20 seconds.
This is my spectrogram:
I would like to have data point on the x axis for every second. I've tries to modify the function timeTicks from the code, but it doesn't work. As an alternative, I've seen that I could zoom in on my spectrogram, but I can't seem to get it to work.
This is the code:
import matplotlib.pyplot as plt
import scipy.io.wavfile as wavfile
cmap = plt.get_cmap('plasma') # this may fail on older versions of matplotlib
vmin = -40 # hide anything below -40 dB
cmap.set_under(color='k', alpha=None)
rate, frames = wavfile.read("audio_test.wav")
fig, ax = plt.subplots()
pxx, freq, t, cax = ax.specgram(frames[:, 0], # first channel
Fs=rate, # to get frequency axis in Hz
cmap=cmap, vmin=vmin)
cbar = fig.colorbar(cax)
cbar.set_label('Intensity dB')
ax.axis("tight")
# Prettify
import matplotlib
import datetime
ax.set_xlabel('time h:mm:ss')
ax.set_ylabel('frequency kHz')
scale = 1e3 # KHz
ticks = matplotlib.ticker.FuncFormatter(lambda x, pos: '{0:g}'.format(x/scale))
ax.yaxis.set_major_formatter(ticks)
def timeTicks(x, pos):
d = datetime.timedelta(seconds=x)
return str(d)
formatter = matplotlib.ticker.FuncFormatter(timeTicks)
ax.xaxis.set_major_formatter(formatter)
ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))
plt.show()
Edit:
The present spectogram:
python matplotlib spectrogram
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
So I've represented a spectrogram for a relatively long video(15 minutes). On the time axis, I've got data points at each 3 minute and 20 seconds.
This is my spectrogram:
I would like to have data point on the x axis for every second. I've tries to modify the function timeTicks from the code, but it doesn't work. As an alternative, I've seen that I could zoom in on my spectrogram, but I can't seem to get it to work.
This is the code:
import matplotlib.pyplot as plt
import scipy.io.wavfile as wavfile
cmap = plt.get_cmap('plasma') # this may fail on older versions of matplotlib
vmin = -40 # hide anything below -40 dB
cmap.set_under(color='k', alpha=None)
rate, frames = wavfile.read("audio_test.wav")
fig, ax = plt.subplots()
pxx, freq, t, cax = ax.specgram(frames[:, 0], # first channel
Fs=rate, # to get frequency axis in Hz
cmap=cmap, vmin=vmin)
cbar = fig.colorbar(cax)
cbar.set_label('Intensity dB')
ax.axis("tight")
# Prettify
import matplotlib
import datetime
ax.set_xlabel('time h:mm:ss')
ax.set_ylabel('frequency kHz')
scale = 1e3 # KHz
ticks = matplotlib.ticker.FuncFormatter(lambda x, pos: '{0:g}'.format(x/scale))
ax.yaxis.set_major_formatter(ticks)
def timeTicks(x, pos):
d = datetime.timedelta(seconds=x)
return str(d)
formatter = matplotlib.ticker.FuncFormatter(timeTicks)
ax.xaxis.set_major_formatter(formatter)
ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))
plt.show()
Edit:
The present spectogram:
python matplotlib spectrogram
python matplotlib spectrogram
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
edited Nov 23 '18 at 5:37
PyRar
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
asked Nov 22 '18 at 22:44
PyRarPyRar
1157
1157
set_major_formatteronly controls how each tick label is written. To control where the ticks are, you need toset_major_locatorwith a tick locator frommatplotlib.dates.
– Joooeey
Nov 23 '18 at 0:08
and if you don't want labels on all your ticks, useset_minor_locator. A label on every second would be too much.
– Joooeey
Nov 23 '18 at 0:09
Thank you for your response @Joooeey! Can't seem to get it done... I've added this line of code: "ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))". I have a weird value after the seconds on the x value. Something like ".001415" and I don't know how to get rid of it. I'll attach a new picture with the present spectrogram.
– PyRar
Nov 23 '18 at 5:36
Try:from matplotlib import datesand thenax.xaxis.set_major_locator(dates.MinuteLocator(interval=2))andax.xaxis.set_minor_locator(dates.SecondLocator()).
– Joooeey
Nov 23 '18 at 17:00
I don't know what the issue with the IndexLocator is, but you can hide the problem by not displaying fractions of a second:ax.xaxis.set_major_formatter(dates.DateFormatter('%H:%M:%S')
– Joooeey
Nov 23 '18 at 17:06
add a comment |
set_major_formatteronly controls how each tick label is written. To control where the ticks are, you need toset_major_locatorwith a tick locator frommatplotlib.dates.
– Joooeey
Nov 23 '18 at 0:08
and if you don't want labels on all your ticks, useset_minor_locator. A label on every second would be too much.
– Joooeey
Nov 23 '18 at 0:09
Thank you for your response @Joooeey! Can't seem to get it done... I've added this line of code: "ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))". I have a weird value after the seconds on the x value. Something like ".001415" and I don't know how to get rid of it. I'll attach a new picture with the present spectrogram.
– PyRar
Nov 23 '18 at 5:36
Try:from matplotlib import datesand thenax.xaxis.set_major_locator(dates.MinuteLocator(interval=2))andax.xaxis.set_minor_locator(dates.SecondLocator()).
– Joooeey
Nov 23 '18 at 17:00
I don't know what the issue with the IndexLocator is, but you can hide the problem by not displaying fractions of a second:ax.xaxis.set_major_formatter(dates.DateFormatter('%H:%M:%S')
– Joooeey
Nov 23 '18 at 17:06
set_major_formatter only controls how each tick label is written. To control where the ticks are, you need to set_major_locator with a tick locator from matplotlib.dates.– Joooeey
Nov 23 '18 at 0:08
set_major_formatter only controls how each tick label is written. To control where the ticks are, you need to set_major_locator with a tick locator from matplotlib.dates.– Joooeey
Nov 23 '18 at 0:08
and if you don't want labels on all your ticks, use
set_minor_locator. A label on every second would be too much.– Joooeey
Nov 23 '18 at 0:09
and if you don't want labels on all your ticks, use
set_minor_locator. A label on every second would be too much.– Joooeey
Nov 23 '18 at 0:09
Thank you for your response @Joooeey! Can't seem to get it done... I've added this line of code: "ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))". I have a weird value after the seconds on the x value. Something like ".001415" and I don't know how to get rid of it. I'll attach a new picture with the present spectrogram.
– PyRar
Nov 23 '18 at 5:36
Thank you for your response @Joooeey! Can't seem to get it done... I've added this line of code: "ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))". I have a weird value after the seconds on the x value. Something like ".001415" and I don't know how to get rid of it. I'll attach a new picture with the present spectrogram.
– PyRar
Nov 23 '18 at 5:36
Try:
from matplotlib import dates and then ax.xaxis.set_major_locator(dates.MinuteLocator(interval=2)) and ax.xaxis.set_minor_locator(dates.SecondLocator()).– Joooeey
Nov 23 '18 at 17:00
Try:
from matplotlib import dates and then ax.xaxis.set_major_locator(dates.MinuteLocator(interval=2)) and ax.xaxis.set_minor_locator(dates.SecondLocator()).– Joooeey
Nov 23 '18 at 17:00
I don't know what the issue with the IndexLocator is, but you can hide the problem by not displaying fractions of a second:
ax.xaxis.set_major_formatter(dates.DateFormatter('%H:%M:%S')– Joooeey
Nov 23 '18 at 17:06
I don't know what the issue with the IndexLocator is, but you can hide the problem by not displaying fractions of a second:
ax.xaxis.set_major_formatter(dates.DateFormatter('%H:%M:%S')– Joooeey
Nov 23 '18 at 17:06
add a comment |
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set_major_formatteronly controls how each tick label is written. To control where the ticks are, you need toset_major_locatorwith a tick locator frommatplotlib.dates.– Joooeey
Nov 23 '18 at 0:08
and if you don't want labels on all your ticks, use
set_minor_locator. A label on every second would be too much.– Joooeey
Nov 23 '18 at 0:09
Thank you for your response @Joooeey! Can't seem to get it done... I've added this line of code: "ax.xaxis.set_major_locator(ticker.IndexLocator(base=180, offset=60))". I have a weird value after the seconds on the x value. Something like ".001415" and I don't know how to get rid of it. I'll attach a new picture with the present spectrogram.
– PyRar
Nov 23 '18 at 5:36
Try:
from matplotlib import datesand thenax.xaxis.set_major_locator(dates.MinuteLocator(interval=2))andax.xaxis.set_minor_locator(dates.SecondLocator()).– Joooeey
Nov 23 '18 at 17:00
I don't know what the issue with the IndexLocator is, but you can hide the problem by not displaying fractions of a second:
ax.xaxis.set_major_formatter(dates.DateFormatter('%H:%M:%S')– Joooeey
Nov 23 '18 at 17:06