Compare floating point numbers in Latex

Question

I am trying to use \ifthenelse to do a floating point comparison. This is the pgf/tikz code, which works if \y is integer only, but not otherwise:

\foreach \y in {3,3.5,...,6} {
    ifthenelse{\y<3}{
        ...
    }{
        ...
    }
}

Answer 1

You can not use floating variables. Use dimens instead of. For example

\newdimen \y 
\y = 3.2pt
\ifdim \y < 3.45pt ... \else ... \fi