emsarray.plot#

emsarray.plot.add_coast(axes, **kwargs)#

Add coastlines to an Axes. Some default styles are applied: the land polygons are light grey and semi-transparent, and the coastlines are opaque dark grey.

Parameters

  • axes (matplotlib.axes.Axes) – The axes to add the coastline to

  • **kwargs – Passed to Axes.add_feature().

emsarray.plot.bounds_to_extent(bounds)#

Convert a Shapely bounds tuple to a matplotlib extents.

A Shapely bounds is a tuple of (min x, min y, max x, max y), while a Matplotlib extent is a list of (min x, max x, min y, max y).

Example

import cartopy.crs as ccrs
import matplotlib.pyplot as plt
from emsarray.plot import bounds_to_extent, polygon_to_patch
from shapely.geometry import Polygon

polygon = Polygon([
    (148.30, -40.75), (146.47, -41.19), (144.67, -40.62),
    (146.05, -43.53), (146.87, -43.60), (148.30, -40.75),
])
figure = plt.figure(figsize=(10, 8), dpi=100)
axes = plt.subplot(projection=ccrs.PlateCarree())
axes.set_extent(bounds_to_extent(polygon.buffer(0.1).bounds))
axes.add_patch(polygon_to_patch(polygon))
figure.show()
emsarray.plot.polygon_to_patch(polygon, **kwargs)#

Convert a shapely.geometry.Polygon to a matplotlib.patches.Polygon.

emsarray.plot.polygons_to_patch_collection(polygons, **kwargs)#

Convert a list of Shapely Polygons to a matplotlib PatchCollection.

Parameters

  • polygons (iterable of Polygon) – The polygons for the patch collection

  • **kwargs (Any) – Keyword arguments to pass to the PatchCollection constructor.

Returns

matplotlib.collections.PatchCollection – The PatchCollection made up of the polygons passed in.

emsarray.plot.plot_on_figure(figure, format, *, scalar=None, vector=None, title=None, projection=None)#

Plot a DataArray on a matplotlib Figure.

Parameters

  • figure – The Figure instace to plot on.

  • format – The Format instance of the dataset. This is used to build the polygons and vector quivers.

  • scalar (xarray.DataArray, optional) – The data to plot as an xarray.DataArray. This will be passed to Format.make_patch_collection().

  • vector (tuple of numpy.ndarray, optional) – The u and v components of a vector field as a tuple of xarray.DataArray. These will be passed to Format.make_quiver().

  • title (str, optional) – The title of the plot. Optional.

  • projection (Projection) – The projection to use when plotting. Optional, defaults to PlateCarree. This is different to the coordinate reference system for the data, which is defined in Format.data_crs.

emsarray.plot.animate_on_figure(figure, format, *, coordinate, scalar=None, vector=None, title=None, projection=None, interval=1000, repeat=True)#

Plot a xarray.DataArray on a matplotlib Figure as a FuncAnimation.

Parameters

  • figure (matplotlib.figure.Figure) – The Figure instace to plot on.

  • format – The Format instance of the dataset. This is used to build the polygons and vector quivers.

  • coordinate (xarray.DataArray) – The coordinate values to vary across frames in the animation.

  • scalar (xarray.DataArray, optional) – The data to plot as an xarray.DataArray. This will be passed to Format.make_patch_collection(). It should have horizontal dimensions appropriate for this format, and a dimension matching the coordinate parameter.

  • vector (tuple of numpy.ndarray, optional) – The u and v components of a vector field as a tuple of xarray.DataArray. These will be passed to Format.make_quiver(). These should have horizontal dimensions appropriate for this format, and a dimension matching the coordinate parameter.

  • title (str or callable, optional) – The title for each frame of animation. Optional, will default to the coordinate value for each frame.

    If this is a string, str.format() will be called with the coordinate value for each frame.

    If this is a callable, it will be called with the coordinate value for each frame, and it should return a string for the title.

  • projection (Projection) – The projection to use when plotting. Optional, defaults to PlateCarree. This is different to the coordinate reference system for the data, which is defined in Format.data_crs.

  • interval (int) – The interval between frames of animation

  • repeat ({True, False, 'cycle', 'bounce'}) – Whether to repeat the animation or not. True and 'cycle' will play the animation on loop forever. 'bounce' will play the animation forward, then backward, then repeat. False will play the animation once then stop.

Returns

matplotlib.animation.Animation