Six methods closing gaps against matplotlib’s Axes API

An audit against matplotlib’s own Axes turned up several plotting methods plotpress didn’t have yet. Six of them, together: bar_label() auto-labeling bar values, arrow()/quiverkey() alongside an existing quiver() field, clabel() labeling contour lines with their values, table() for a grid of cells, indicate_inset_zoom() marking the region an inset zooms into, and barbs() for wind-barb symbols.

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import numpy as np
import plotpress

fig, axes = plotpress.subplots(2, 3, figsize=(15.0, 9.0))

# -- bar_label(): auto-label each bar with its own value ---------------
ax = axes[0, 0]
bars = ax.bar([0, 1, 2, 3], [3.2, -1.8, 5.1, 1.4], color="#2ca02c")
ax.bar_label(bars, padding=2)
ax.set_title("bar_label()")

# -- arrow() + quiver() + quiverkey() -----------------------------------
ax = axes[0, 1]
X, Y = np.meshgrid(np.linspace(0.5, 3.5, 4), np.linspace(0.5, 3.5, 4))
Q = ax.quiver(X, Y, np.ones_like(X) * 0.3, np.ones_like(Y) * 0.1, color="#1f77b4")
ax.arrow(1.0, 1.0, 1.5, 1.2, color="#d62728")   # a single, separately-placed arrow
ax.set_xlim(0, 4.5)
ax.set_ylim(0, 4.5)
# quiverkey() needs the axes' final limits already set -- it resolves its
# own axes-fraction (X, Y) to a data point at call time, not at render time
# the way text()'s transform=ax.transAxes does.
ax.quiverkey(Q, 0.85, 0.95, 0.3, "0.3 units/step", coordinates="axes")
ax.set_title("arrow() + quiver() + quiverkey()")

# -- clabel(): label contour lines with their level values --------------
ax = axes[0, 2]
g = np.linspace(-2, 2, 60)
Xc, Yc = np.meshgrid(g, g)
Z = np.exp(-(Xc ** 2 + Yc ** 2)) - 0.5 * np.exp(-((Xc - 1) ** 2 + (Yc - 1) ** 2) * 2)
CS = ax.contour(g, g, Z, levels=6)
ax.clabel(CS, fontsize=7)
ax.set_title("clabel()")

# -- table(): a grid of cells, axes-fraction positioned ------------------
ax = axes[1, 0]
ax.plot([0, 1, 2], [0, 1, 0.5], color="#1f77b4")
ax.table(cellText=[["1.2", "3.4"], ["5.6", "7.8"]], rowLabels=["A", "B"],
         colLabels=["X", "Y"], loc="lower right",
         cellColours=[["#eef", "#eef"], ["#fee", "#fee"]])
ax.set_title("table()")

# -- indicate_inset_zoom(): mark what region an inset shows --------------
ax = axes[1, 1]
xd = np.linspace(0, 10, 300)
ax.plot(xd, np.sin(xd), color="#1f77b4")
inset = ax.inset_axes([0.55, 0.55, 0.4, 0.4])
inset.plot(xd, np.sin(xd), color="#1f77b4")
inset.set_xlim(2, 4)
inset.set_ylim(-1, 1)
inset.set_xticks([])
inset.set_yticks([])
ax.indicate_inset_zoom(inset)
ax.set_title("indicate_inset_zoom()")

# -- barbs(): wind barbs, speed 2 to 65 ------------------------------------
ax = axes[1, 2]
Xb, Yb = np.meshgrid(np.arange(5), np.arange(5))
Ub = np.linspace(2, 65, 25).reshape(5, 5)
Vb = np.full((5, 5), 15.0)
ax.barbs(Xb, Yb, Ub, Vb, length=6, color="#333333")
ax.set_xlim(-1, 5)
ax.set_ylim(-1, 5)
ax.set_title("barbs()")

fig.suptitle("New Axes methods, closing gaps against matplotlib's own API")
fig.tight_layout()