General ⇒ Doing modulus with counters

[angelixd]

I would like to be able to do something dependent on whether or not a counter is even. something like

Code: Select all

\include{ifthen}
...
\ifthenelse{\isEven{mycounter}}
           {% code for even case
           }
           {% code for odd case
           }

\newcommand{\isEven}[1]{
   \ifthenelse{ ??? }{TRUE}{FALSE}

}

The only thing is doing calculations in LaTeX is like pulling teeth, and I'm sure as hell that '%' is not a mathematical modulus operator... I've read through the calc package looking for clues, but I couldn't find any leads. Does anyone know i'd go about writing \isEven{} ?

[gmedina]

You can use the \isodd command to test whether a given number is odd; in the following simple example the \myExample command will write its argument in \Huge size if \myCounter has an odd value and will write its argument in \tiny size if the counter has an even value.

Code: Select all

\documentclass{article}
\usepackage{ifthen}
\newcounter{myCounter}
\newcommand{\myExample}[1]%
 {\ifthenelse{\isodd{\themyCounter}}{\Huge #1 \par}{\tiny #1 \par}}

\begin{document}
\stepcounter{myCounter}
\myExample{text}
\stepcounter{myCounter}
\myExample{text}
\end{document}

Edit: I corrected some spelling issues

[balfonsi]

It's much simpler than what you think: there is an \isodd command defined by the ifthen package. So you just have to write

\ifthenelse{\isodd{\value{myCounter}} {%code for oddcase%
}{%code for even case%
}%

Btw, % is just a comment sign for the rest of the line.

Best regards,
B.A.

[angelixd]

Hey guys, thanks a whole bunch. Time to get to work!