\documentclass[11pt]{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.3}

\begin{document}
\begin{tikzpicture}
\begin{axis}[xlabel=x,ylabel=y,no markers]
\addplot plot[error bars/.cd,y dir=plus,y explicit,error mark=diamond*] coordinates {
(0, 0.22507) +- (0,0.99741)
(1, 0.22507) +- (0,nan)
(2,  0.22507)+- (0,0.99741)
(3, 0.22507)+- (0,nan)
};
\end{axis}
\end{tikzpicture}
%
\begin{tikzpicture}
\begin{axis}[xlabel=x,ylabel=y,no markers]
\addplot plot[error bars/.cd,y dir=plus,y explicit relative,error mark=diamond*] coordinates {
(0, 0.22507) +- (0,0.99741)
(1, 0.22507) +- (0,nan)
(2,  0.22507)+- (0,0.99741)
(3, 0.22507)+- (0,nan)
};
\end{axis}
\end{tikzpicture}

\begin{tikzpicture}
\begin{axis}[xlabel=x,ylabel=y,no markers]
\addplot plot[error bars/.cd,y dir=plus,y explicit,error mark=diamond*] table[x=x,y=ind2,y error=ind3] {
x  ind2    ind3
0  0.22507 0.99741
1  0.22507 nan
2  0.22507 0.99741
3  0.22507 nan
};
\end{axis}
\end{tikzpicture}
\end{document}


