Can't use \pgfmathdeclarefunction even though I use package pgfplots?

Question

Possible Duplicate:
How do I use pgfmathdeclarefunction to create define a new pgf function?

I'm running the simple code:

\documentclass{minimal}
\usepackage{pgfplots}

\pgfmathdeclarefunction{p}{1}{%
  \pgfmathand{\pgfmathless{#1}{1}} {\pgfmathgreater{#1}{0}}%
}

\begin{document}

\begin{tikzpicture}
  \begin{axis}
    \addplot {p(x)};
  \end{axis}
\end{tikzpicture}

\end{document}

I get:

! Undefined controlsequence.

1.4 \pgfmathdeclarefunction

Any ideas what might be wrong? Other examples with pgf seem to work just fine.

If it helps, I'm using TexShop for mac. I have the most recent version.

I don't get the error you describe, but get ! Extra \else. \pgfmath@operation@@process Following defining-a-piecewise-function-for-pgfplots and using \pgfmathdeclarefunction{p}{1}{\pgfmathparse{(and(#1>0, #1<1)*1)}} everything works fine. Is your tex distribution up to date? ` — cmhughes, Mar 19 '12 at 03:07
I'm usin Texshop for mac. I just downloaded the last version but I still get the same error. — Skuge, Mar 19 '12 at 05:07
TeXShop is just an editor, not the tex distribution that does the actual typesetting. And Welcome to TeX.SE. — Peter Grill, Mar 19 '12 at 05:17

score 2 · Accepted Answer · answered Mar 19 '12 at 05:14

2

I believe this has something to do with expansion when using the \pgfmath... type functions within other \pgfmth....

But what does work is if you rewrite the function as:

 \pgfmathand{less({#1},1)}{greater({#1},0)}

This yields:

enter image description here

\documentclass{article}
\usepackage{pgfplots}

\pgfmathdeclarefunction{p}{1}{%
  \pgfmathand{less({#1},1)}{greater({#1},0)}%
}

\begin{document}
\begin{tikzpicture}
  \begin{axis}
    \addplot {p(x)};
  \end{axis}
\end{tikzpicture}
\end{document}

answered Mar 19 '12 at 05:14

Peter Grill

223,288

or with \pgfmathparse{and(less(#1,1),greater(#1,0))} – Alain Matthes Mar 19 '12 at 07:51
@Altermundus: Yep, or as per cmhughes' comment above. I was trying to keep it as close to the original post.. – Peter Grill Mar 19 '12 at 13:54

score 1 · Answer 2 · edited Mar 19 '12 at 07:10

1

So it wasn't a problem with TexShop but a problem with TikZ. \pgfmathdeclarefunction is only available on the latest build.

Installing the package again should solve the problem.

Download Tikz

edited Mar 19 '12 at 07:10

Torbjørn T.

206,688

answered Mar 19 '12 at 05:16

Skuge

284

The builds found at TeXample are somewhat old, Altermundus have more recent builds. Also, \pgfmathdeclarefunction is found in the latest stable versions I believe (the build above is a development version), so simply updating your TeX distribution should help. – Torbjørn T. Mar 19 '12 at 07:13

Can't use \pgfmathdeclarefunction even though I use package pgfplots?

2 Answers2