我遇到了以下问题。我的目标是用 tikz 构建一个条形图。使用函数显示堆叠 ybar 中条形的总和，我想在 x 轴下方为一个特定总和添加上标。
show sum below/.style={
/pgfplots/scatter/@post marker code/.append code={%
\node[font=\footnotesize,
at={(normalized axis cs:%
\pgfkeysvalueof{/data point/x},%
0)%
},
anchor=north,
] {
\ifnum\pgfmathparse{\pgfkeysvalueof{/data point/y}}=2,500
{\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}}\textsuperscript{$3$}};
\else
{\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}}};
\fi};
},
},
在此代码中，x 轴下方的总和显示基本上是相应条的最高点。
不幸的是，我在将 /数据点/y 移交给 if 子句时遇到了问题。
有什么想法可以解决这个问题以便为条件建立正确的输入？
下面是一个最小工作示例：
\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{threeparttable}
\usepackage{tikz}
\usetikzlibrary{arrows,decorations.pathmorphing,backgrounds,fit,positioning,shapes.symbols,chains, calligraphy}
\usepackage{pgfplots, pgfplotstable}
\pgfplotsset{
compat=1.14,
}
\begin{document}
\begin{figure}[th]
\centering
\begin{threeparttable}[t]
\begin{tabular}{@{}c@{}}
\begin{tikzpicture}
\edef\mylst{"1963", "1964"}
\pgfplotsset{
show sum below/.style={
/pgfplots/scatter/@post marker code/.append code={%
\node[font=\footnotesize,
at={(normalized axis cs:%
\pgfkeysvalueof{/data point/x},%
0)%
},
anchor=north,
] {
\ifnum\pgfmathparse{\pgfkeysvalueof{/data point/y}}=375
{\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}}\textsuperscript{$3$}};
\else
{\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}}};
\fi};
},
},
}
\begin{axis}[
ybar stacked,
xticklabels={{1963}, {1964}},
symbolic x coords = {{1963}, {1964}},
axis y line = none,
axis x line = none,
nodes={text width=25mm, text depth=,
align=center, font=\tiny},
nodes near coords={\pgfmathprintnumber\pgfplotspointmeta},
scale only axis,
]
% Data 1
\addplot[text=black
] coordinates {
({1963}, 50)
({1964}, 125)
};
% Data 2
\addplot[text=black
] coordinates {
({1963}, 250)
({1964}, 250)
};
% Total
% Here point meta=explicit symbolic to hide the helping values 1e-500 as 0 leads to hiding sums
\addplot[show sum below, point meta=explicit symbolic] coordinates {
({1963}, 1e-500)
({1964}, 1e-500)
};
\end{axis}
\end{tikzpicture}
\end{tabular}
\begin{tablenotes}\footnotesize
\item[$1$] Comment numero uno
\end{tablenotes}
\end{threeparttable}%
\end{figure}
\end{document}
答案1
您不能使用\ifnum\pgfmathparse{...}=375，因为\pgfmathparse无法通过扩展起作用。
您还应该将数据转换为可以实际使用的格式。
% first parse the number
\pgfmathfloatparsenumber{\pgfkeysvalueof{/data point/y}}
% then store in \pgfmathresult the value in fixed point notation
\pgfmathfloattofixed{\pgfmathresult}
% store 1 if equal and 0 otherwise in \pgfmathresult
\pgfmathparse{\pgfmathresult==375 ? 1 : 0}
% now look whether we have equality or not
\ifnum\pgfmathresult=1
你会成功的。
在第一次调用中，的连续值\pgfmathresult将是
1Y3.0e2]
300.00000000
0
在第二次通话中
1Y3.75e2]
375.000000000
1
完整代码
\documentclass[12pt]{article}
\usepackage{threeparttable}
\usepackage{tikz}
\usetikzlibrary{
arrows,
decorations.pathmorphing,
backgrounds,
fit,
positioning,
shapes.symbols,
chains,
calligraphy
}
\usepackage{pgfplots, pgfplotstable}
\pgfplotsset{
compat=1.14,
}
\begin{document}
\begin{figure}[htp]
\centering
\begin{threeparttable}[t]
\begin{tabular}{@{}c@{}}
\begin{tikzpicture}
\def\mylst{"1963", "1964"}
\pgfplotsset{
show sum below/.style={
/pgfplots/scatter/@post marker code/.append code={
\node[
font=\footnotesize,
at={(normalized axis cs:\pgfkeysvalueof{/data point/x},0)},
anchor=north,
]{
\pgfmathfloatparsenumber{\pgfkeysvalueof{/data point/y}}
\pgfmathfloattofixed{\pgfmathresult}
\pgfmathparse{\pgfmathresult==375 ? 1 : 0}
\ifnum\pgfmathresult=1
\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}}\textsuperscript{$3$};
\else
\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}};
\fi
};
},
},
}
\begin{axis}[
ybar stacked,
xticklabels={{1963}, {1964}},
symbolic x coords = {{1963}, {1964}},
axis y line = none,
axis x line = none,
nodes={
text width=25mm,
text depth=,
align=center,
font=\tiny
},
nodes near coords={\pgfmathprintnumber\pgfplotspointmeta},
scale only axis,
]
% Data 1
\addplot[text=black] coordinates {
({1963}, 50)
({1964}, 125)
};
% Data 2
\addplot[text=black] coordinates {
({1963}, 250)
({1964}, 250)
};
% Total
% Here point meta=explicit symbolic to hide the helping values 1e-500 as 0 leads to hiding sums
\addplot[show sum below, point meta=explicit symbolic] coordinates {
({1963}, 1e-500)
({1964}, 1e-500)
};
\end{axis}
\end{tikzpicture}
\end{tabular}
\begin{tablenotes}\footnotesize
\item[$1$] Comment numero uno
\end{tablenotes}
\end{threeparttable}
\end{figure}
\end{document}
答案2
问题是数据值\pgfkeysvalueof{/data point/y}以浮点格式存储。（此外，\ifnum\pgfmathparse无论如何都不能用于这种组合。）为了使用，\ifnum您希望它是一个纯整数。所以你需要转换它。下面的代码可以做到这一点，但可能不是最简单的方式。
\pgfkeys{/pgf/fpu,/pgf/fpu/output format=fixed}%
\pgfmathsetmacro\myy{\pgfkeysvalueof{/data point/y}}%
\pgfkeys{/pgf/fpu=false}%
此外，在 pgf 中进行比较通常很有优势，因为这也适用于非整数。
\pgfmathtruncatemacro\itest{\myy==375}%
\itest然后就可以安全地在语句中使用结果了\ifnum。
\documentclass[12pt]{article}
\usepackage{threeparttable}
\usepackage{pgfplots}
\pgfplotsset{compat=1.14}
\begin{document}
\begin{figure}[th]
\centering
\begin{threeparttable}[t]
\begin{tabular}{@{}c@{}}
\begin{tikzpicture}
\edef\mylst{"1963", "1964"}
\pgfplotsset{
show sum below/.style={
/pgfplots/scatter/@post marker code/.append code={%
\node[font=\footnotesize,
at={(normalized axis cs:%
\pgfkeysvalueof{/data point/x},%
0)%
},
anchor=north,
] {\begingroup
\pgfkeys{/pgf/fpu,/pgf/fpu/output format=fixed}%
\pgfmathsetmacro\myy{\pgfkeysvalueof{/data point/y}}%
\pgfkeys{/pgf/fpu=false}%
\pgfmathtruncatemacro\itest{\myy==375}%
\ifnum\itest=0
{\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}}\textsuperscript{$3$}};
\else
{\pgfmathprintnumber{\pgfkeysvalueof{/data point/y}}};
\fi
\endgroup
};
},
},
}
\begin{axis}[
ybar stacked,
xticklabels={{1963}, {1964}},
symbolic x coords = {{1963}, {1964}},
axis y line = none,
axis x line = none,
nodes={text width=25mm, text depth=,
align=center, font=\tiny},
nodes near coords={\pgfmathprintnumber\pgfplotspointmeta},
scale only axis,
]
% Data 1
\addplot[text=black
] coordinates {
({1963}, 50)
({1964}, 125)
};
% Data 2
\addplot[text=black
] coordinates {
({1963}, 250)
({1964}, 250)
};
% Total
% Here point meta=explicit symbolic to hide the helping values 1e-500 as 0 leads to hiding sums
\addplot[show sum below, point meta=explicit symbolic] coordinates {
({1963}, 1e-500)
({1964}, 1e-500)
};
\end{axis}
\end{tikzpicture}
\end{tabular}
\begin{tablenotes}\footnotesize
\item[$1$] Comment numero uno
\end{tablenotes}
\end{threeparttable}%
\end{figure}
\end{document}