亲爱的，我尝试生成直方图/条形图
结果.csv：
overlap,hit,organism
100,274,Unknowns
100,228,Coccomyxa subellipsoidea
100,11,Eukaryota
-500,153,Unknowns
-500,145,Coccomyxa subellipsoidea
-500,7,Eukaryota
-1000,118,Unknowns
-1000,108,Coccomyxa subellipsoidea
-1000,4,cellular organisms
-2000,74,Coccomyxa subellipsoide
-2000,72,Unknowns
-2000,4,Viridiplantae
-4000,51,Unknowns
-4000,42,Coccomyxa subellipsoidea
-4000,2,Eukaryota
-8000,26,Coccomyxa subellipsoidea
-8000,25,Unknowns
-8000,1,Eukaryota
-16000,14,Coccomyxa subellipsoidea
-16000,13,Unknowns
-16000,1,cellular organisms
如您所见，我们可以使用重叠将数据分为 7 个类别：
100、-500、-1000、-2000、-4000、-8000、-16000
\documentclass[table]{beamer}
\usepackage[american]{babel}
\usepackage{etex}
\usepackage{pgfplots}
\usepackage{xcolor}
\usepackage{listings}
\usepackage{textcomp}
\usepackage{tikz}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\pgfplotsset{
compat = newest,
table/col sep = comma
}
\begin{document}
\begin{frame}
\begin{tikzpicture}
\pgfplotstableread{result.csv}\table
\centering
\begin{axis}[
visualization depends on={value \thisrow{organism} \as \labela},
visualization depends on={value \thisrow{hit} \as \labelb},
ybar,
height = 6cm,
width = 10cm,
enlarge y limits = false,
axis lines* = left,
ymin = 0,
ymax = 300,
xmin = -17000,
xmax = 600,
legend style = {
at = {(0.5,-0.2)},
anchor = north,
legend columns = -1
},
xtick = data,
scaled y ticks = false,
y tick label style = {/pgf/number format/fixed,/pgf/number format/1000 sep = \thinspace},
xticklabels from table= \table{overlap},
nodes near coords={\labela/\pgfmathprintnumber\labelb},
every node near coord/.append style={ anchor=mid west, rotate=80 }
]
\foreach \i in {1,2,...,21}{
\addplot table[ x index=\i, y index=1 ] \table;
}
\end{axis}
\end{tikzpicture}
\end{frame}
\end{document}
但我无法正确绘图，当前代码给出错误：
! Package PGF Math Error: Could not parse input 'Unknowns' as a floating point
number, sorry. The unreadable part was near 'Unknowns'.
感谢您的帮助
答案1
要使用字符串作为条形图的标签，您可以通过在图表选项中point meta=explicit symbolic设置来使用并指定将哪一列用作每个图表的标签。meta=<column name>table
在这种情况下，我将重新组织数据表，按重叠部分对生物体和命中次数进行分组：
\documentclass{article}
\usepackage{pgfplots, xstring}
\pgfplotsset{compat=newest}
\usepackage{filecontents}
\begin{filecontents}{dataedited.csv}
overlap,hit1,organism1,hit2,organism2,hit3,organism3
100,274,Unknowns,228,Coccomyxa subellipsoidea,11,Eukaryota
-500,153,Unknowns,145,Coccomyxa subellipsoidea,7,Eukaryota
-1000,118,Unknowns,108,Coccomyxa subellipsoidea,4,cellular organisms
-2000,74,Coccomyxa subellipsoide,72,Unknowns,4,Viridiplantae
-4000,51,Unknowns,42,Coccomyxa subellipsoidea,2,Eukaryota
-8000,26,Coccomyxa subellipsoidea,25,Unknowns,1,Eukaryota
-16000,14,Coccomyxa subellipsoidea,13,Unknowns,1,cellular organisms
\end{filecontents}
\begin{document}
\begin{tikzpicture}
\pgfplotstableread[col sep=comma]{dataedited.csv}\table
\centering
\begin{axis}[
xbar, bar width=7pt,
height = 11cm,
width = 10cm,
enlarge x limits = false,
axis lines* = left,
legend style = {
at = {(0.5,-0.2)},
anchor = north,
legend columns = -1
},
xmin = 0,
ytick = data,
scaled x ticks = false,
yticklabels from table= \table{overlap},
point meta=explicit symbolic,
nodes near coords={
\IfStrEq{\pgfplotspointmeta}{Coccomyxa subellipsoidea}{\textcolor{red}{\pgfplotspointmeta}}{\pgfplotspointmeta}
},
every node near coord/.append style={anchor=mid west, yshift=-0.5ex, black!75}
]
\addplot [fill=gray] table [col sep=comma, y expr=-\coordindex, x=hit3, meta=organism3] {dataedited.csv};
\addplot [fill=gray!75] table [col sep=comma, y expr=-\coordindex, x=hit2, meta=organism2] {dataedited.csv};
\addplot [fill=gray!50] table [col sep=comma, y expr=-\coordindex, x=hit1, meta=organism1] {dataedited.csv};
\end{axis}
\end{tikzpicture}
\end{document}