pgf 绘制单个刻度标签位置

Question

我怎样才能在 Latex 中做到这一点？

我目前得到的是：

\begin{tikzpicture}
\begin{axis}[
width=6cm,
height=6cm,
x axis line style={-stealth},
y axis line style={-stealth},
title={Signal 1},
xticklabels={},
ymax = 1.5,xmax=4,
axis lines*=center,
ytick={-1,1},yticklabels={$-\hat{i}$,$\hat{i}$},
xtick={1,2,3},xticklabels={$\frac{T}{3}$,$\frac{2T}{3}$,$T$},

%ticklabel style={at={(1,0)},xshift=1.5ex, anchor=north},
xlabel={$t$},
ylabel={$i(t)$},
every axis x label/.style={
    at={(ticklabel* cs:1.05)},
    anchor=west,
},
every axis y label/.style={
    at={(ticklabel* cs:1.05)},
    anchor=south,
},]
\addplot+[line width=0.5mm,mark=none,const plot]
coordinates
{(0,0) (0,1) (1,-1) (2,-1) (2,0) (3,0) (3,1) (4,1)};
\end{axis}
\end{tikzpicture}

据我所知，额外的刻度不起作用，因为所有标签都必须移动到不同的位置。

Answer 1

纯tikz：

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{arrows.meta}

\begin{document}
    \begin{tikzpicture}[
tick/.style = {inner sep=1pt, font=\scriptsize}
                        ]
% axis
\draw[-Straight Barb]   (-0.2,0) -- + (4,0) node[right] {$t$};
    \foreach \x [count=\ix] in {\frac{T}{3}, \frac{2T}{3}, T}
        \node[tick,below right] at (\ix,0) {$\x$};
\draw[-Straight Barb]   (0,-1.2) -- + (0,2.4) node[above] {$i(t)$};
    \draw (0,-1) -- + (-0.1,0) node[tick,left] {$-\hat{\imath}$};
    \draw (0, 1) -- + (-0.1,0) node[tick,left] {$ \hat{\imath}$};
% function
\draw[line width=0.5mm, blue] plot coordinates
    {(0,0) (0,1) (1,1) (1,-1) (2,-1) (2,0) (3,0) (3,1) (3.5,1)};
    \end{tikzpicture}
\end{document}

Answer 2

您pgfplots可以使用\hspace{}水平移动 x 标签，并使用extra x tick style和xtra x ticks放置您想要应用不同样式的标签：

xtick={1,3},
xticklabels={\hspace*{2.0ex}$\frac{T}{3}$,$T$},
extra x tick style={x tick label style={above, yshift=0.6ex}},
extra x ticks={2},

得出的结果是：

代码：

\documentclass{article}
\usepackage{pgfplots}
\usepackage{graphicx}

\begin{document}
\begin{tikzpicture}
\begin{axis}[
    width=6cm,
    height=6cm,
    x axis line style={-stealth},
    y axis line style={-stealth},
    title={Signal 1},
    %xticklabels={},% <--- Of no use, since it is redefined later
    ymax = 1.5,xmax=4,
    axis lines*=center,
    ytick={-1,1},
    yticklabels={$-\hat{i}$,$\hat{i}$},
    xtick={1,3},
    xticklabels={\hspace*{2.0ex}$\frac{T}{3}$,$T$},
    extra x tick style={x tick label style={above, yshift=0.6ex}},
    extra x ticks={2},
    %ticklabel style={at={(1,0)},xshift=1.5ex, anchor=north},
    xlabel={$t$},
    ylabel={$i(t)$},
    every axis x label/.style={
        at={(ticklabel* cs:1.05)},
        anchor=west,
    },
    every axis y label/.style={
        at={(ticklabel* cs:1.05)},
        anchor=south,
    },
]
    \addplot+[line width=0.5mm,mark=none,const plot]
    coordinates
    {(0,0) (0,1) (1,-1) (2,-1) (2,0) (3,0) (3,1) (4,1)};
\end{axis}
\end{tikzpicture}%
\end{document}