WradlibAccessor.plot(ax=111, fig=None, proj=None, func='pcolormesh', cmap='viridis', center=False, add_colorbar=False, add_labels=False, **kwargs)

Plot Plan Position Indicator (PPI) or Range Height Indicator (RHI).

The implementation of this plot routine is in cartesian axes and does all coordinate transforms using xarray machinery. This allows zooming into the data as well as making it easier to plot additional data (like gauge locations) without having to convert them to the radar’s polar coordinate system.

Using proj='cg' the plotting is done in a curvelinear grid axes.

Additional data can be plotted in polar coordinates or cartesian coordinates depending which axes object is used.

**kwargs may be used to try to influence the matplotlib.pyplot.pcolormesh, matplotlib.pyplot.contour, matplotlib.pyplot.contourf and wradlib.georef.polar.spherical_to_proj routines under the hood.

  • proj (cartopy CRS | curvelinear grid dict | None) – cartopy CRS Coordinate Reference System describing projection If this parameter is not None, site must be set properly. Then the function will attempt to georeference the radar bins and display the PPI in the coordinate system defined by the projection string.
  • fig (matplotlib.figure.Figure) – If given, the PPI/RHI will be plotted into this figure object. Axes are created as needed. If None, a new figure object will be created or current figure will be used, depending on ax.
  • ax (matplotlib.axes.Axes | matplotlib grid) –
  • definition – If matplotlib Axes object is given, the PPI will be plotted into this axes object. If matplotlib grid definition is given (nrows/ncols/plotnumber), axis are created in the specified place. Defaults to ‘111’, only one subplot/axis.
  • func (str) – Name of plotting function to be used under the hood. Defaults to ‘pcolormesh’. ‘contour’ and ‘contourf’ can be selected too.
  • cmap (str) – matplotlib colormap string

pm (matplotlib.collections.QuadMesh | matplotlib.contour.QuadContourSet) – The result of the plotting function. Necessary, if you want to add a colorbar to the plot.


If proj contains a curvelinear grid dict, the cgax - curvelinear Axes (r-theta-grid) is returned. caax - Cartesian Axes (x-y-grid) and paax - parasite axes object for plotting polar data can be derived like this:

caax = cgax.parasites[0]
paax = cgax.parasites[1]

The function create_cg uses the Matplotlib AXISARTIST namespace mpl_toolkits.axisartist.

Here are some limitations to normal Matplotlib Axes. See AxesGridToolkitUserGuide.


See Quick-view a sweep in polar or cartesian reference systems, and Plot data to curvelinear grid.