如何为曲线区间填充颜色？

Question

\documentclass{article}

\usepackage{pgfplots}
\usepackage{pgfplotstable}
\usepackage{amssymb, amsmath}
\pgfplotsset{compat=1.8}

\begin{document}

\pgfmathdeclarefunction{gauss}{3}{%
    \pgfmathparse{1/(#3*sqrt(2*pi))*exp(-((#1-#2)^2)/(2*#3^2))}%
}

\begin{tikzpicture}
\begin{axis}[
no markers, 
domain=0:6, 
samples=100,
ymin=0,
axis lines*=left, 
%xlabel=$x$,
every axis y label/.style={at=(current axis.above origin),anchor=south},
every axis x label/.style={at=(current axis.right of origin),anchor=west},
height=5cm, 
width=12cm,
xtick=\empty, 
ytick=\empty,
enlargelimits=false, 
clip=false, 
axis on top,
grid = major,
hide y axis
]

\addplot [very thick,cyan!50!black] {gauss(x, 3, 1)};

\pgfmathsetmacro\valueA{gauss(1,3,1)}
\pgfmathsetmacro\valueB{gauss(2,3,1)}

\draw [gray] (axis cs:3,0) -- (axis cs:3,0.4)
 (axis cs:4.2,0) -- (axis cs:4.2,0.19);



\node[below] at (axis cs:4.2, 0)  {$1.2$}; 
\node[below] at (axis cs:3, 0)  {$0$}; 
\end{axis}



\end{tikzpicture}

\end{document}

我想为区间 $0 \leq z \leq 1.2 $ 填充颜色，我该怎么做？

Answer 1

对于最高版本 1.10，您可以在曲线青色图之前添加以下代码（而不是之后，以实现最佳剪辑）：

\addplot[
    fill=cyan!50,
    draw=none,
    domain=3:4.2,
    ] {gauss(x,3,1)} \closedcycle;
]