我将使用以下命令绘制条形直方图：
\documentclass[a4paper]{report}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\begin{document}
\begin{tikzpicture}
\centering
\begin{axis}[
xbar,
height=4.5cm,
width=13cm,
bar width=0.2cm,
legend style={at={(0.5,-0.21)},
enlarge x limits={upper,value=0.25},
xmin=-2,xmax=110,
anchor=north,legend columns=-1},
ylabel={\ Data size}, xlabel={\ Computation time(sec)},
symbolic y coords={1024 by 1024,512 by 512,256 by 256},
ytick=data,
nodes near coords,
nodes near coords align=horizontal,
]
\addplot coordinates {(108.3,1024 by 1024) (14.22,512 by 512) (1.7,256 by 256)
};
\addplot coordinates {(3.5,1024 by 1024) (0.85,512 by 512) (0.21,256 by 256)
};
\legend{Conventional method,Butterfly-based method}
\end{axis}
\end{tikzpicture}
\end{document}
但是我的直方图不在页面的中心，我的表格是这样的：
我怎样才能将其放置在页面左右两侧的中间位置？我怎样才能减少列之间的空间？
答案1
\centering之后\begin{tikzpicture}不执行任何操作：使用center环境，但也使用相对宽度，因为 13cm 对于文本宽度来说很可能太大。
\documentclass[a4paper]{report}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\begin{document}
\begin{center}
\begin{tikzpicture}
\begin{axis}[
xbar,
height=4.5cm,
width=.8\textwidth, % <------- relative width
bar width=0.2cm,
legend style={at={(0.5,-0.21)},
enlarge x limits={upper,value=0.25},
xmin=-2,xmax=110,
anchor=north,legend columns=-1},
ylabel={\ Data size},
xlabel={\ Computation time(sec)},
symbolic y coords={1024 by 1024,512 by 512,256 by 256},
ytick=data,
nodes near coords,
nodes near coords align=horizontal,
]
\addplot coordinates {(108.3,1024 by 1024) (14.22,512 by 512) (1.7,256 by 256)
};
\addplot coordinates {(3.5,1024 by 1024) (0.85,512 by 512) (0.21,256 by 256)
};
\legend{Conventional method,Butterfly-based method}
\end{axis}
\end{tikzpicture}
\end{center}
\end{document}
如果你有一个figure围绕情节的环境，那么你应该输入
\begin{figure}
\centering
\begin{tikzpicture}
...
\end{tikzpicture}
\caption{The caption}\label{thelabel}
\end{figure}
为了制作图片，我使用了该showframe包，因此显示了文本块的边界。
