Note
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Contours
The pygmt.Figure.contour
method can plot contour lines from a table of
points by direct triangulation. The data for the triangulation can be provided
using one of three methods:
x
,y
,z
1-Dnumpy.ndarray
data columns.data
2-Dnumpy.ndarray
data matrix with 3 columns corresponding tox
,y
,z
.data
path string to a file containing thex
,y
,z
in a tabular format.
The parameters levels
and annotation
set the intervals of the contours
and the annotation on the contours respectively.
In this example we supply the data as 1-D numpy.ndarray
with the
x
, y
, and z
parameters and draw the contours using a 0.5p pen with
contours every 10 z
values and annotations every 20 z
values.
![contours](../../_images/sphx_glr_contours_001.png)
import numpy as np
import pygmt
# build the contours underlying data with the function z = x^2 + y^2
X, Y = np.meshgrid(np.linspace(-10, 10, 50), np.linspace(-10, 10, 50))
Z = X**2 + Y**2
x, y, z = X.flatten(), Y.flatten(), Z.flatten()
fig = pygmt.Figure()
fig.contour(
region=[-10, 10, -10, 10],
projection="X10c/10c",
frame="ag",
pen="0.5p",
# pass the data as 3 1-D data columns
x=x,
y=y,
z=z,
# set the contours z values intervals to 10
levels=10,
# set the contours annotation intervals to 20
annotation=20,
)
fig.show()
Total running time of the script: (0 minutes 0.226 seconds)