[Tex/LaTex] Using PGF in Lyx

Question

I just tried coping & pasting code from How to draw Venn diagrams (especially: complements) in LaTeX

and I get errors … I suppose I need to install/configure Lyx to use PGF/Tikz?

Answer 1

You need to add \usepackage{pgfplots} to your preamble. In LyX, you can edit the preamble under Document | Settings | LaTeX Preamble.