Convenient methods to plot horizontal and vertical lines

Description of the desired feature

matplotlib provides two methods, hlines and vlines, for plotting horizontal and vertical lines.

In PyGMT, we can plot any lines using the plot() method. However, for plotting horizontal and vertical lines, we have to prepare the input x and y arrays, which is not elegant.

Expected syntax:

Figure.hlines(y, xmin=None, xmax=None, pen=None, label=None)
Figure.vlines(x, ymin=None, ymax=None, pen=None, label=None)

An expected hlines example:

import pygmt
fig = pygmt.Figure()
fig.basemap(region=[0, 10, 0, 10], projection="X10c/10c", frame=True)
fig.hlines(1, label="line1")
fig.hlines([2, 3], pen="1p,blue", label="line2")
fig.hlines([4, 5], xmin=2, xmax=8, pen="1p,red", label="line3")
fig.hlines([6, 7], xmin=[2, 3], xmax=[8, 9], pen="1p,lightblue", label=["line4", "line5"])
fig.legend()
fig.show()

Expected output:

The above script is equivalent to the following script:

import pygmt
fig = pygmt.Figure()
fig.basemap(region=[0, 10, 0, 10], projection="X10c/10c", frame=True)
fig.plot(x=[0, 10], y=[1, 1], label="line1")
fig.plot(x=[0, 10], y=[2, 2], pen="1p,blue", label="line2")
fig.plot(x=[0, 10], y=[3, 3], pen="1p,blue")
fig.plot(x=[2, 8], y=[4, 4], pen="1p,red", label="line3")
fig.plot(x=[2, 8], y=[5, 5], pen="1p,red")
fig.plot(x=[2, 8], y=[6, 6], pen="1p,lightblue", label="line4")
fig.plot(x=[3, 9], y=[7, 7], pen="1p,lightblue")
fig.legend()
fig.show()

Are you willing to help implement and maintain this feature? Yes

[willschlitzer]

@michaelgrund Haven’t made any progress lately; by all means have a stab at it!

[michaelgrund]

Are you still working on that issue @willschlitzer? If not and if it’s ok for you I would like to continue with that 😉