Set the region argument

Many of the plotting functions take an argument for the region argument, which sets the area that will be shown in the figure. This tutorial covers the different types of inputs that it can accept.

import pygmt

Coordinates

A string of coordinates can be passed to region, in the form of xmin/xmax/ymin/ymax.

fig = pygmt.Figure()
fig.coast(
    # Sets the x-range from 10E to 20E and the y-range to 35N to 45N
    region="10/20/35/45",
    # Set projection to Mercator, and the figure size to 15 centimeters
    projection="M15c",
    # Set the color of the land to light gray
    land="lightgray",
    # Set the color of the water to white
    water="white",
    # Display the national borders and set the pen-size to 0.5p
    borders="1/0.5p",
    # Display the shorelines and set the pen-size to 0.5p
    shorelines="1/0.5p",
    # Set the frame to automatic and display gridlines
    frame="ag",
)
fig.show()

Out:

<IPython.core.display.Image object>

The coordinates coordinates can be passed to region as a list, in the form of

[xmin,*xmax*,*ymin*,*ymax*].

fig = pygmt.Figure()
fig.coast(
    # Sets the x-range from 10E to 20E and the y-range to 35N to 45N
    region=[10, 20, 35, 45],
    projection="M12c",
    land="lightgray",
    water="white",
    borders="1/0.5p",
    shorelines="1/0.5p",
    frame="ag",
)
fig.show()

Out:

<IPython.core.display.Image object>

GMT has the option for region coordinates to be passed in classic mode, which was the standard prior to GMT version 6. The string format takes the coordinates for the bottom-left and top-right coordinates. To specify classic mode, append +r at the end of the region string.

fig = pygmt.Figure()
fig.coast(
    # Sets the bottom-left corner as 10E, 35N and the top-right corner as 20E, 45N
    region="10/35/20/45+r",
    projection="M12c",
    land="lightgray",
    water="white",
    borders="1/0.5p",
    shorelines="1/0.5p",
    frame="ag",
)
fig.show()

Out:

<IPython.core.display.Image object>

Passing g to region sets the region to

fig = pygmt.Figure()
fig.coast(
    region="g", projection="Cyl_stere/12c", land="tomato1", water="skyblue", frame="ag"
)
fig.show()

Out:

<IPython.core.display.Image object>