\ProvidesPackage{shadedgauss}

% This package renders shaded gaussian curves.
% by Kevin Pluck kevinjpluck@gmail.com

% Usage:
% \midshadedgauss{mean}{std.dev}{xmin}{xmax}{start of shaded area}{end of shaded area}
% \leftshadedgauss{mean}{std.dev}{xmin}{xmax}{end of shaded area}
% \rightshadedgauss{mean}{std.dev}{xmin}{xmax}{start of shaded area}

% A good rule of thumb for xmin and xmax is mean +/- 2.5*std.dev.

\usepackage{tikz}
\usepackage{pgfplots}

\pgfmathdeclarefunction{gauss}{2}{%
	  \pgfmathparse{1/(#2*sqrt(2*pi))*exp(-((x-#1)^2)/(2*#2^2))}%
	}
	
	\newcommand{\midshadedgauss}[6]{
		\begin{center}
			\begin{tikzpicture}
				\begin{axis}[
					domain=#3:#4, samples=100,
					axis y line = none,
					axis x line* = bottom,
					height=3cm, width=7.2cm, font=\tiny,
					xtick={#1,#5,#6},ytick=\empty,
					enlargelimits=false, axis on top,
					grid = major
				  ]
				  \addplot [fill=cyan!20, draw=none, domain=#5:#6] {gauss(#1,#2)} \closedcycle;
				  \addplot [very thick,cyan!50!black] {gauss(#1,#2)};
				\end{axis}
			\end{tikzpicture}
		\end{center}
	}
	
	\newcommand{\leftshadedgauss}[5]{
		\begin{center}
			\begin{tikzpicture}
				\begin{axis}[
					domain=#3:#4, samples=100,
					axis y line = none,
					axis x line* = bottom,
					height=3cm, width=7.2cm, font=\tiny,
					xtick={#1,#5},ytick=\empty,
					enlargelimits=false, axis on top,
					grid = major
				  ]
				  \addplot [fill=cyan!20, draw=none, domain=#3:#5] {gauss(#1,#2)} \closedcycle;
				  \addplot [very thick,cyan!50!black] {gauss(#1,#2)};
				\end{axis}
			\end{tikzpicture}
		\end{center}

	}
	
	\newcommand{\rightshadedgauss}[5]{
		\begin{center}
			\begin{tikzpicture}
				\begin{axis}[
					domain=#3:#4, samples=100,
					axis y line = none,
					axis x line* = bottom,
					height=3cm, width=7.2cm, font=\tiny,
					xtick={#1,#5},ytick=\empty,
					enlargelimits=false, axis on top,
					grid = major
				  ]
				  \addplot [fill=cyan!20, draw=none, domain=#5:#4] {gauss(#1,#2)} \closedcycle;
				  \addplot [very thick,cyan!50!black] {gauss(#1,#2)};
				\end{axis}
			\end{tikzpicture}
		\end{center}

	}