as discussed over in bug #51839, and recently brought up again in https://octave.discourse.group/t/how-to-make-a-polar-plot-from-3d-data/4966,  neither octave nor matlab have a function that easily modifies the values of the tick labels for plots created with the polar function.  In matlab, the newer polarplot class produces polar objects that can be edited directly and with the functions rticklabels and tticklabels, which perform similarly to xticklabels.

As the actual procedure for modifying these labels is rather cumbersome, and involves digging into hidden child handles and understanding the arbitrary handle ordering, this patch report is a placeholder for octave implementations of both functions that will work on plots from polar just like the xticklabels functions.  This will be a known expansion of the functions beyond matlab capability, as matlab produces an error if either r- or tticklabels is called on anything other than a polarplot object, but if (when?) octave does rework plot objects to be able to produce a real polarplot object, it should just be a matter of overloading these functions for that new class.