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Plotting r,theta (radar) data

To plot (r,theta) data, you must convert the coordinates to a cartesian space. NCL doesn't currently have the ability to plot this kind of data directly.
radar_1.ncl: A simple example of creating contours from (r, theta) coordinates. Note the calculations that are done to create 2D coordinates in X and Y.

The first frame is done using raster fill (cnFillMode = "RasterFill"). The second frame is done using cell fill (cnFillMode = "CellFill"), which allows you to additionally set cnMissingValFillColor to fill the missing value areas in some color.

radar_2.ncl: This is similar to the first example on this page, but using a CF radial dataset.
radar_3.ncl: This example shows how to create a radial background plot and then attach different colored markers to it (using dummy data).

The main funtion for creating the radial plot is "radial_plot". This function calls three different procedures for creating the radial lines (add_radial_lines), the circles (add_radial_circles), and the labels around the outer circle (add_radial_labels).

Note: this example may change if we get some better examples of plotting radar data.

radar_4.ncl: This example uses a modified version of map tickmarks to create a nice set of labels for a radar plot.

It was contributed by Chris Fletcher from the University of Waterloo.

radar_5.ncl: This example shows how to create a radar plot by plotting the random points using raster-filled contours. It uses a color table called radar_qinrui.rgb.

This example creates a panel plot where each plot uses a different part of the colormap, via the use of gsnSpreadColorStart and gsnSpreadColorEnd.

This example was contributed by Qin Rui of the Beijing Weather Modification Office.