Note
Click here to download the full example code
Adding an inset to the figure
To plot an inset figure inside another larger figure, we can use the
pygmt.Figure.inset
method. After a large figure has been created,
call inset
using a with
statement, and new plot elements will be
added to the inset figure instead of the larger figure.
import pygmt
Prior to creating an inset figure, a larger figure must first be plotted. In
the example below, pygmt.Figure.coast
is used to create a map of the
US state of Massachusetts.
fig = pygmt.Figure()
fig.coast(
region=[-74, -69.5, 41, 43], # Set bounding box of the large figure
borders="2/thin", # Plot state boundaries with thin lines
shorelines="thin", # Plot coastline with thin lines
projection="M15c", # Set Mercator projection and size of 15 centimeter
land="lightyellow", # Color land areas light yellow
water="lightblue", # Color water areas light blue
frame="a", # Set frame with annotation and major tick spacing
)
fig.show()
Out:
<IPython.core.display.Image object>
The pygmt.Figure.inset
method uses a context manager, and is called
using a with
statement. The position
parameter, including the inset
width, is required to plot the inset. Using the j argument, the location
of the inset is set to one of the 9 anchors (bottom-middle-top and
left-center-right). In the example below, BL
sets the inset to the bottom
left. The box
parameter can set the fill and border of the inset. In the
example below, +pblack
sets the border color to black and +gred
sets
the fill to red.
fig = pygmt.Figure()
fig.coast(
region=[-74, -69.5, 41, 43],
borders="2/thin",
shorelines="thin",
projection="M15c",
land="lightyellow",
water="lightblue",
frame="a",
)
with fig.inset(position="jBL+w3c", box="+pblack+glightred"):
# pass is used to exit the with statement as no plotting functions are
# called
pass
fig.show()
Out:
<IPython.core.display.Image object>
When using j to set the anchor of the inset, the default location is in contact with the nearby axis or axes. The offset of the inset can be set with +o, followed by the offsets along the x- and y-axis. If only one offset is passed, it is applied to both axes. Each offset can have its own unit. In the example below, the inset is shifted 0.5 centimeters on the x-axis and 0.2 centimeters on the y-axis.
fig = pygmt.Figure()
fig.coast(
region=[-74, -69.5, 41, 43],
borders="2/thin",
shorelines="thin",
projection="M15c",
land="lightyellow",
water="lightblue",
frame="a",
)
with fig.inset(position="jBL+w3c+o0.5c/0.2c", box="+pblack+glightred"):
pass
fig.show()
Out:
<IPython.core.display.Image object>
Standard plotting functions can be called from within the inset
context
manager. The example below uses pygmt.Figure.coast
to plot a zoomed
out map that selectively paints the state of Massachusetts to shows its
location relative to other states.
fig = pygmt.Figure()
fig.coast(
region=[-74, -69.5, 41, 43],
borders="2/thin",
shorelines="thin",
projection="M15c",
land="lightyellow",
water="lightblue",
frame="a",
)
# This does not include an inset fill as it is covered by the inset figure
with fig.inset(position="jBL+w3c+o0.5c/0.2c", box="+pblack"):
# Use a plotting function to create a figure inside the inset
fig.coast(
region=[-80, -65, 35, 50],
projection="M3c",
land="gray",
borders=[1, 2],
shorelines="1/thin",
water="white",
# Use dcw to selectively highlight an area
dcw="US.MA+gred",
)
fig.show()
Out:
<IPython.core.display.Image object>
Total running time of the script: ( 0 minutes 5.157 seconds)