读取数据时将分类值映射到样式

Question

由于您使用常规 Ti 绘制图钾Z 命令，我可能不会使用axis环境来绘制轴。在axis环境中，由于扩展，无论你使用什么工具，循环都不容易。

另外，您可能想看看可以pgfplotstable完美集成到 Ti 中的包钾Z/PGF 宇宙。

您可以使用backgrounds库来解决方框覆盖注释的问题。我猜，需要做更多的工作才能避免标签相互覆盖。

至于颜色，您可以像区域一样命名它们。这样，您就完全解决了映射问题。只要区域名称不包含某些特殊字符，这种方法就没问题。

以下代码基于您作为答案发布的代码：

\documentclass[border=10pt]{standalone}

\usepackage{pgfplotstable}
\pgfplotsset{compat=1.18}
\usetikzlibrary{backgrounds}

% Predefined colors per geographical area.
\definecolor{Oceania}{HTML}{C9C900}
\definecolor{North America}{HTML}{FF9900}
\definecolor{Europe}{HTML}{008080}
\definecolor{Middle East and North Africa}{HTML}{009900}
\definecolor{South America}{HTML}{660099}
\definecolor{Central America and Caribbean}{HTML}{b2004c}
\definecolor{Asia}{HTML}{ff0000}
\definecolor{Sub-Saharian Africa}{HTML}{0000cd}

\begin{filecontents*}{ghg_countries.csv}
georegion,country,population,ghgcapita
Oceania,Australia,0.025203200000000002,24.143
Oceania,New Zealand,0.004783062,15.176
Oceania,Papua New Guinea,0.008776119,7.232
North America,Canada,0.03741104,20.697
North America,United States,0.329064896,17.538
Middle East and North Africa,Qatar,0.0028320710000000002,40.522
Middle East and North Africa,United Arab Emirates,0.009770526,24.927
Middle East and North Africa,Saudi Arabia,0.034268528,21.102
Middle East and North Africa,Iran,0.082913888,10.78
Middle East and North Africa,Turkey,0.083429608,5.512
Middle East and North Africa,Egypt,0.10038808,3.506
South America,Paraguay,0.007044639,13.713
South America,Venezuela,0.028515828000000003,10.506
South America,Argentina,0.044780676000000005,8.908
South America,Brazil,0.21104952000000002,6.878
South America,Chile,0.018952036000000002,2.919
Europe,Ireland,0.004882498,12.018
Europe,Netherlands,0.017097124000000002,10.153
Europe,Germany,0.08351704800000001,8.624
Europe,United Kingdom,0.067530168,6.355
Europe,France,0.06512973200000001,5.406
Asia,South Korea,0.051225320000000005,12.741
Asia,Japan,0.126860296,8.943
Asia,China,1.433783808,8.408
Asia,Indonesia,0.27062556800000004,7.241
Asia,Thailand,0.06962557600000001,6.279
Asia,Vietnam,0.096462112,4.542
Asia,Myanmar,0.054045420000000004,4.495
Asia,India,1.366417792,2.462
Asia,Philippines,0.10811662400000001,2.19
Asia,Pakistan,0.216565312,2.029
Asia,Afghanistan,0.038041756,0.757
Central America and Caribbean,Mexico,0.12757552800000002,5.258
Central America and Caribbean,Cuba,0.011333484000000001,3.37
Central America and Caribbean,Haiti,0.011263079,0.988
Sub-Saharian Africa,Botswana,0.0023037030000000003,22.72
Sub-Saharian Africa,South Africa,0.058558264000000006,9.601
Sub-Saharian Africa,Zimbabwe,0.014645473,8.054
Sub-Saharian Africa,Democratic Republic of Congo,0.086790568,7.83
Sub-Saharian Africa,Mozambique,0.030366042000000003,3.515
Sub-Saharian Africa,Tanzania,0.05800546,2.67
Sub-Saharian Africa,Nigeria,0.200963616,1.763
Sub-Saharian Africa,Ethiopia,0.112078728,1.636
Sub-Saharian Africa,Kenya,0.052573968000000006,1.396
Sub-Saharian Africa,Ghana,0.030417858000000002,0.419
\end{filecontents*}

\pgfplotstableread[col sep=comma]{ghg_countries.csv}\datatable
\pgfplotstablegetrowsof{\datatable}
\pgfmathtruncatemacro{\datarowcount}{\pgfplotsretval-1}

\begin{document}

\begin{tikzpicture}[y=0.33cm, x=1.5cm, axis/.style={draw=gray, very thin}]
    \draw[axis] (0,30) coordinate (plot north west) |- (8,0) coordinate (plot south east) 
        node[pos=0.25, left=1cm, rotate=90, anchor=center] {Greenhouse gas pollution (tons $\mathrm{CO_2e/y}$ per person)} 
        node[pos=0.75, below=0.75cm, anchor=center] {population (billions)};
    
    \path (plot north west) -- (plot north west -| plot south east) 
        node[pos=0.5, above] {Greenhouse gas emissions per country (2019)};       
             
    \foreach \x in {0,...,8} {
        \draw[axis] (\x,0) -- (\x,-2.5pt) node[below] {\x};
    }
    
    \foreach \y in {0,5,...,30} {
        \draw[axis] (0,\y) -- (-2.5pt,\y) node[left] {\y};
    }

    \pgfmathsetmacro{\offset}{0}
    \foreach [remember=\offset] \i in {0,...,\datarowcount}{
        \pgfplotstablegetelem{\i}{georegion}\of{\datatable}
        \let\georegion\pgfplotsretval
        \pgfplotstablegetelem{\i}{country}\of{\datatable}
        \let\country\pgfplotsretval
        \pgfplotstablegetelem{\i}{population}\of{\datatable}
        \let\population\pgfplotsretval
        \pgfplotstablegetelem{\i}{ghgcapita}\of{\datatable}
        \let\ghgcapita\pgfplotsretval
        
        \begin{pgfonlayer}{background}
            \draw[\georegion, fill=\georegion!10] 
                (\offset, 0) rectangle +(\population, \ghgcapita) coordinate (corner);
        \end{pgfonlayer}
        
        \pgfmathparse{ifthenelse(\population > 4e-2 || \ghgcapita > 15, 1, 0)}
        \ifnum\pgfmathresult=1\relax
            \draw[latex-] (corner) -- +(45:4mm)
                node[anchor=west, rotate=45, font=\footnotesize] {\country};
        \fi
        
        \pgfmathsetmacro{\offset}{\offset + \population}
    }
\end{tikzpicture}
\end{document}

Answer 1