latex tikz 循环填充颜色

Question

我想在折线图中填充一些颜色，代码如下：

\begin{tikzpicture}
\begin{axis}[
        xmin=0.09,
        xmax=0.32,
        ymin=0,
        ymax=230,
        ylabel=$num$,
        xlabel=$ratio$,
        height=6cm,
        width=8cm,
        grid=major,]
\addplot [black, fill=red!20] plot [smooth] 
    coordinates {
    (0.09, 196)
    (0.1 , 215)
    (0.11, 207)
    (0.12, 203)
    (0.13, 205)
    (0.14, 191)
    (0.15, 194)
    (0.16, 193)
    (0.17, 180)
    (0.18, 159)
    (0.19, 130)
    (0.2 , 78)
    (0.21, 71)
    (0.22, 59)
    (0.23, 70)
    (0.24, 55)
    (0.25, 54)
    (0.26, 48)
    (0.27, 46)
    (0.28, 48)
    (0.29, 54)
    (0.3 , 45)}
     -- (0.09,0)-- (0.3,0) -- cycle;
\end{axis}
\end{tikzpicture} 

但我得到的是这样的数值？

有人知道为什么该区域没有关闭吗？谢谢。

Answer 1

可以告诉 tikz 使用水平线和垂直线而不是直线|-：

\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
        xmin=0.09,
        xmax=0.32,
        ymin=0,
        ymax=230,
        ylabel=$num$,
        xlabel=$ratio$,
        height=6cm,
        width=8cm,
        grid=major,]
\addplot [black, fill=red!20] plot [smooth] 
    coordinates {
    (0.09, 196)
    (0.1 , 215)
    (0.11, 207)
    (0.12, 203)
    (0.13, 205)
    (0.14, 191)
    (0.15, 194)
    (0.16, 193)
    (0.17, 180)
    (0.18, 159)
    (0.19, 130)
    (0.2 , 78)
    (0.21, 71)
    (0.22, 59)
    (0.23, 70)
    (0.24, 55)
    (0.25, 54)
    (0.26, 48)
    (0.27, 46)
    (0.28, 48)
    (0.29, 54)
    (0.3 , 45)}
      |- (0,0) |- cycle;
\end{axis}
\end{tikzpicture} 
\end{document}