I have some numeric data in matrix form, which for the sake of discussion is the values of some function f(x,y) sampled at some discrete grid. This data is, say, in a .csv file or in an .ods (LibreOffice Calc) / .xlsx (Excel) table; of course I can change formats if necessary.
I want to generate a heatmap for this data: A rectangular image which, at each (x,y) position, has color whose intensity is proportional to to some reasonable interpolation of f(x,y) using the sample data.
Now, the Wikipedia page has a bunch of links to software which produces one kind or another of heat maps, but I'm interested in a comparison among them, with respect to:
- Intuitivity of use
- Ease of input ingestion
- Support for infinte-resolution maps
- Ability to produce output files in various formats
- Configurability and tweakability (color palettes, value ranges, transforming values with a specified function, generating just the values at the grid points or generating them as overlays, labels etc.))
Also, are there formats which support generating svg's which somehow support heatmaps intrinsically, i.e. using two-variable gradient area coloring?
(I'm secretly hoping for a LibreOffice plugin, but I guess there isn't one.)
- Libre, Gratis and Open-Source, unless it's some Excel add-on
- Linux, preferably also Windows
Edit: While I have accepted an answer, other options are still very welcome, especially ones with a GUI.