translate plotmath latex

Question

I started using the awesome knitr package, and whilst I love the idea of using tikz graphics, it's not always very practical (time consuming). Thus, I end up switching back and forth between the good old pdf device, and tikz. Mathematical expressions are generally not handled in the same way in both devices; I find it much preferable to use LaTeX syntax in tikz, but it becomes hard to read in pdf, and vice-versa.

Have there been attempts at providing a framework to seamlessly switch from one notation to another? Something like a translate(x, from="plotmath", to="tex", ams=TRUE, ...) function, that could be hooked internally with knitr to the device in use. How would one go about doing it?

Answer 1

This sounds hard to me. Translation from plotmath to LaTeX may be easier, e.g. replace alpha with \alpha, and x[i] with x_{i}, etc, but the other way can be difficult since plotmath is only a "subset" of LaTeX expressions.

If the time-consuming generation of tikz graphics is an issue for you, you may consider turning on the cache (as I did in the knitr manual and many other example documents). Once a tikz figure is generated, it will not be regenerated the next time if cache=TRUE, so it will be pretty fast, and it will be even faster if you also convert tikz to pdf by the chunk option external=TRUE.

The only reason that I may not use tikz is when the plot is too large in size, as I explained in the manual. Other than that, tikz is always preferable to me. This is slightly off-topic, though.