Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Ability to define custom projection. #166

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Ability to define custom projection. #166

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
38 changes: 25 additions & 13 deletions lib/catnip/visualisation.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,15 +32,20 @@


import matplotlib

matplotlib.use("Agg")
import matplotlib.pyplot as plt
import iris.quickplot as qplt
import doctest
import iris
from catnip.analysis import linear_regress, ci_interval
import numpy as np
import cartopy.crs as ccrs


def vector_plot(u_cube, v_cube, unrotate=False, npts=30, num_plot=111, title=""):
def vector_plot(
u_cube, v_cube, unrotate=False, npts=30, num_plot=111, title="", projection=None
):
"""
A plotting function to produce a quick wind
vector plot. Output is a plot with windspeed
Expand All @@ -64,14 +69,8 @@ def vector_plot(u_cube, v_cube, unrotate=False, npts=30, num_plot=111, title="")
"""

# x and y coords
try:
x = u_cube.coord(axis="x")
except iris.exceptions.CoordinateNotFoundError:
print("Error: more than one x coord found")
try:
y = u_cube.coord(axis="y")
except iris.exceptions.CoordinateNotFoundError:
print("Error: more than one y coord found")
x = u_cube.coord(axis="x")
y = u_cube.coord(axis="y")

# if the wind vectors need to be unrotated
# they are in the statement below
Expand All @@ -92,19 +91,32 @@ def vector_plot(u_cube, v_cube, unrotate=False, npts=30, num_plot=111, title="")
windspeed_cube = (u_cube ** 2 + v_cube ** 2) ** 0.5

# plot
transform = x.coord_system.as_cartopy_projection()
# use coord_system of input data to define plot projection
ax = plt.subplot(num_plot, projection=transform)
# use coord_system of input data to define plot projection if not specified by user
if projection is None:
if x.coord_system is None:
projection = ccrs.PlateCarree()
else:
projection = x.coord_system.as_cartopy_projection()

# the original crs of the data is needed for quiver plot and setting extents
if x.coord_system is None:
print("No crs found, assuming PlateCarree")
orig_crs = ccrs.PlateCarree()
else:
orig_crs = x.coord_system.as_cartopy_projection()

ax = plt.subplot(num_plot, projection=projection)
qplt.contourf(windspeed_cube, 20)
ax.quiver(
u_cube.coord(x.standard_name).points[::npts],
v_cube.coord(y.standard_name).points[::npts],
u_cube.data[::npts, ::npts],
v_cube.data[::npts, ::npts],
transform=orig_crs,
)
# OTHER OPTIONS FOR QUIVER: scale = 1, headwidth = 3, width = 0.0015)
ax.coastlines()
ax.set_extent([x.points[0], x.points[-1], y.points[0], y.points[-1]], transform)
ax.set_extent([x.points[0], x.points[-1], y.points[0], y.points[-1]], crs=orig_crs)
plt.title(title)
print("plot {} created".format(title))

Expand Down