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"""
=======
Barcode
=======
This demo shows how to produce a bar code.
The figure size is calculated so that the width in pixels is a multiple of the
number of data points to prevent interpolation artifacts. Additionally, the
``Axes`` is defined to span the whole figure and all ``Axis`` are turned off.
The data itself is rendered with `~.Axes.imshow` using
- ``code.reshape(1, -1)`` to turn the data into a 2D array with one row.
- ``imshow(..., aspect='auto')`` to allow for non-square pixels.
- ``imshow(..., interpolation='nearest')`` to prevent blurred edges. This
should not happen anyway because we fine-tuned the figure width in pixels,
but just to be safe.
"""
import matplotlib.pyplot as plt
import numpy as np
code = np.array([
1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1,
0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0,
1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1,
1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1])
pixel_per_bar = 4
dpi = 100
fig = plt.figure(figsize=(len(code) * pixel_per_bar / dpi, 2), dpi=dpi)
ax = fig.add_axes([0, 0, 1, 1]) # span the whole figure
ax.set_axis_off()
ax.imshow(code.reshape(1, -1), cmap='binary', aspect='auto',
interpolation='nearest')
plt.show()
# %%
#
# .. admonition:: References
#
# The use of the following functions, methods, classes and modules is shown
# in this example:
#
# - `matplotlib.axes.Axes.imshow` / `matplotlib.pyplot.imshow`
# - `matplotlib.figure.Figure.add_axes`
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