使用 Basemap 的 robin 投影和 contourf 数据问题

Question

我正在使用底图库显示来自哥白尼程序的空间信息。问题是我不知道如何在知更鸟投影上投影数据，但我用正交投影正确地做到了。

所以目前，我试过这个：

plt.ioff()

    # adapt for location of datasources
    filePath = '../data/grib/download.grib'

    # load data
    grbs = grb.open(filePath)
    grbs.seek(0)

    data, lats, lons = (None, None, None)
    dataUnit = None
    title = None
    for g in grbs:
        data, lats, lons = g.data()

        name = g.name
        level = g.level
        pressureUnit = g.pressureUnits
        date = g.validDate

        dataUnit = g.units

        title = name + ' at ' + str(level) + ' ' + str(pressureUnit) + ' [' + str(date) + ']'
        print(title)

        break

#     mapPlot = Basemap(projection='ortho', lat_0=0, lon_0=0)
    mapPlot = Basemap(projection='robin', lat_0=0, lon_0=0, resolution='l')
    mapPlot.drawcoastlines(linewidth=0.25)

    x, y = mapPlot(lons, lats)
    mapPlot.contourf(x, y, data)
    mapPlot.colorbar(location='bottom', format='%.1f', label=dataUnit)

    plt.title(title)
    plt.show()

正交投影工作正常。但是对于知更鸟投影，我有一个......有趣的模式。

我做错了什么？

Answer 1

所以我想办法了。我被误导了，但我看到的第一个例子。

这是我的代码：


        import matplotlib
        from mpl_toolkits.basemap import Basemap, shiftgrid

        import matplotlib.pyplot as plt
        import numpy as np
        import pygrib as grb

        # Get data
        data = g['values']
        lats = g['distinctLatitudes'] # 1D vector
        lons = g['distinctLongitudes'] # 1D vector

        # Useful information for late
        name = g.name
        level = str(g.level) + g.pressureUnits
        date = g.validDate
        dataUnit = g.units

        # Parse the data
        # Shit the data to start à -180. This is important to mark the data to start at -180°
        data, lons = shiftgrid(180., data, lons, start=False)  # shiftgrid

        # Choose a representation (works with both)
#         mapPlot = Basemap(projection='ortho', lat_0=0, lon_0=0)
        mapPlot = Basemap(projection='robin', lat_0=0, lon_0=0)
        mapPlot.drawcoastlines(linewidth=0.25)

        # Convert the coordinates into the map projection
        x, y = mapPlot(*np.meshgrid(lons, lats))

        # Display data
        map = mapPlot.contourf(x, y, data, levels=boundaries, cmap=plt.get_cmap('coolwarm'))

        # Add what ever you want to your map.
        mapPlot.nightshade(date, alpha=0.1)

        # Legend
        mapPlot.colorbar(map, label=dataUnit)

        # Title
        plt.title(name + ' at ' + str(level) + ' [' + str(date) + ']')

        plt.show()

这就是 returns 我所期待的。

使用 Basemap 的 robin 投影和 contourf 数据问题

Issue with the robin projection and contourf data with Basemap

projection

grib

matplotlib-basemap