plotting.py

# coding=utf-8

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import numpy as np
import matplotlib.pyplot as plt
import cartopy
import cartopy.crs as ccrs


def plot_sphere(data, fig=None, cmap="RdBu", title=None, colorbar=False, coastlines=False, gridlines=False, central_latitude=0, central_longitude=0, lon=None, lat=None, **kwargs):
    if fig == None:
        fig = plt.figure()

    nlat = data.shape[-2]
    nlon = data.shape[-1]
    if lon is None:
        lon = np.linspace(0, 2 * np.pi, nlon)
    if lat is None:
        lat = np.linspace(np.pi / 2.0, -np.pi / 2.0, nlat)
    Lon, Lat = np.meshgrid(lon, lat)

    proj = ccrs.Orthographic(central_longitude=central_longitude, central_latitude=central_latitude)
    # proj = ccrs.Mollweide(central_longitude=central_longitude)

    ax = fig.add_subplot(projection=proj)
    Lon = Lon * 180 / np.pi
    Lat = Lat * 180 / np.pi

    # contour data over the map.
    im = ax.pcolormesh(Lon, Lat, data, cmap=cmap, transform=ccrs.PlateCarree(), antialiased=False, **kwargs)
    if coastlines:
        ax.add_feature(cartopy.feature.COASTLINE, edgecolor="white", facecolor="none", linewidth=1.5)
    if gridlines:
        gl = ax.gridlines(crs=ccrs.PlateCarree(), draw_labels=False, linewidth=1.5, color="gray", alpha=0.6, linestyle="--")
    if colorbar:
        plt.colorbar(im, extend="both")
    plt.title(title, y=1.05)

    return im


def plot_data(data, fig=None, cmap="RdBu", title=None, colorbar=False, coastlines=False, gridlines=False, central_longitude=0, lon=None, lat=None, **kwargs):
    if fig == None:
        fig = plt.figure()

    nlat = data.shape[-2]
    nlon = data.shape[-1]
    if lon is None:
        lon = np.linspace(0, 2 * np.pi, nlon)
    if lat is None:
        lat = np.linspace(np.pi / 2.0, -np.pi / 2.0, nlat)
    Lon, Lat = np.meshgrid(lon, lat)

    proj = ccrs.PlateCarree(central_longitude=central_longitude)
    # proj = ccrs.Mollweide(central_longitude=central_longitude)

    ax = fig.add_subplot(projection=proj)
    Lon = Lon * 180 / np.pi
    Lat = Lat * 180 / np.pi

    # contour data over the map.
    im = ax.pcolormesh(Lon, Lat, data, cmap=cmap, transform=ccrs.PlateCarree(), antialiased=False, **kwargs)
    if coastlines:
        ax.add_feature(cartopy.feature.COASTLINE, edgecolor="white", facecolor="none", linewidth=1.5)
    if gridlines:
        gl = ax.gridlines(crs=ccrs.PlateCarree(), draw_labels=False, linewidth=1.5, color="gray", alpha=0.6, linestyle="--")
    if colorbar:
        plt.colorbar(im, extend="both")
    plt.title(title, y=1.05)

    return im