I am new to Python, as the ideas behind Holoviz lured me away from R and ggplot.
However, I am having some trouble when it comes to plotting, and I am not sure where I can learn more.
I have a boatload of netCDF (.nc) files with meteorological data. I made them into an xarray.Dataset, then called geoviews.Dataset on this. When I print the geoviews.Dataset or even convert it to geoviews.FilledContours, I get exactly what I want. This was good and easy to do, thanks to the extensive xarray documentation and the many geoviews examples which show these particular steps.
Now that I have a basic FilledContours plot, I want to customize it. The most important thing is that values below a certain threshold are a neutral background color (white in this case), while the contours are deeper shades on a selected color (blue).
Typing “geoviews.help(geoviews.FilledContours)” brings up the list of parameters. Some of these are very helpful. Others are not.
When I apply cbar_levels, the plot behaves exactly as I expect it to. However, when I use cbar_ticks in the same manner, I get pathological nonsense (ticks do not correspond to bins, and they are also scaled differently from the bins, which were specified in very same manner). The help screen leads me to believe cbar_levels and cbar_ticks behave in the same way. I tried to find the source code for geoviews.opts.FilledContours, but to no avail. I thought the logical place would be here, but it’s not. I’ve also combed through many other_init_.py files within matplotlib and geoviews with the same luck.
Holoviz is composed of many parts. matplotlib and geoviews are directly related to this, and other packages may be hidden in the background. With this in mind, if I want to learn the effects of geoviews.opts.<some_plot_type> parameters, where should I look?
If there is not an existing example in the gallery already, are you just SoL and need to find the place in the source code? I am probably missing something.
Edit: I think I figured out my particular problem by trying every combination of relevant parameters I could, however my larger problem remains: how can I reliably find these things out without spending a good portion of the day?