This pages answers a few questions about swak4Foam that pop up frequently on the message board

### Is it possible to have lookup-tables with more than one independent variable?

`tl;dr`: No, it isn't.

swak4Foam offers one-dimensional lookup-tables where you can lookup 1-dimensional functions from tabulated data `f(x)`. An often requested feature is to have multi-dimensional lookup tables `g(x,t)` or `h(x,y,z)`. These are not present in swak for a number of reasons:

- In most applications where this is requested it is usually possible to separate the function into two independent functions (or similar)
- Another batch of applications can be handled by the built-in
`timeVaryingMappedFixedValue` - There is no applicable multi-dimensional interpolation of data in OpenFOAM and the implementation is not that trivial (handling of invalid data, handling outside of range requests etc)
- There is no generally accepted data-format for the multidimensional data (I often requested people to specify what they would see as a common data format for this but nobody cared to answer)

This feature **may** be implemented in the future but there are no concrete plans for this (of course if somebody wants to implement it and contribute the patches ...)