Add simple time series plotting function

Hey,

I just thought of adding a little helper function to the display module which simply plots a time series. Basically a plt.plot() but uses the librosa.display.TimeFormatter. I have this already as a helper function and it comes in handy in times where you might have 1d-features with different sampling rate and want to compare them…whatever, no big deal. Is this interesting as a general function?

Code

import numpy as np
import matplotlib.pyplot as plt

import librosa
import librosa.display


sr = 10

x = np.random.rand(100)

plt.figure(figsize=(10, 6))
times = librosa.samples_to_time(np.arange(len(x)), sr=sr)
plt.plot(times, x)
plt.gca().xaxis.set_major_formatter(librosa.display.TimeFormatter(lag=False))
plt.gca().xaxis.set_label_text('Time')

plt.show()

[bmcfee]

I propose that this feature be rolled into #1207

[lostanlen]

Color-code the waveform according to a perceptual audio feature (e.g. spectral brightness à la Traktor) and you’ve got a unique viz in the Pythonic landscape here ☺️