Merge pull request #470 from rdrehmel/doc

Fix the phi(m) function.

Author: hmenke

doc/latex/pgfplots/pgfplots.reference.markers-meta.tex

@@ -3918,7 +3918,7 @@ \subsection{User Input Format for Point Meta}
     a function
         \[ \phi\colon [m_{\min},m_{\max}] \to [0,1000] \]
     with
-        \[ \phi(m) = \frac{m - m_{\min}} {1000} \]
+        \[ \phi(m) = \frac{m - m_{\min}}{m_{\max} - m_{\min}} \cdot 1000 \]
     such that $\phi(m_{\min}) = 0$ and $\phi(m_{\max})=1000$. The value $1000$
     is -- per convention -- the upper limit of all color maps. Now, if a
     coordinate (or edge/face) has the point meta data $m$, its color will be