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线性不等式图

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线性不等式图

我从以下代码获得：https://tex.stackexchange.com/a/76014/10898

在此处输入图片描述

\documentclass{article} 

\usepackage{pgfplots} 
\usetikzlibrary{patterns}

\makeatletter
\newcommand{\pgfplotsdrawaxis}{\pgfplots@draw@axis}
\makeatother
\pgfplotsset{only axis on top/.style={axis on top=false, after end axis/.code={
             \pgfplotsset{axis line style=opaque, ticklabel style=opaque, tick style=opaque,
                          grid=none}\pgfplotsdrawaxis}}}

\newcommand{\drawge}{-- (rel axis cs:1,0) -- (rel axis cs:1,1) -- (rel axis cs:0,1) \closedcycle}
\newcommand{\drawle}{-- (rel axis cs:1,1) -- (rel axis cs:1,0) -- (rel axis cs:0,0) \closedcycle}

\begin{document} 
  \begin{figure}[htpb] 
    \centering 
    \label{fig:p3:c1} 
    \begin{tikzpicture} 
      \begin{axis}[only axis on top,
        axis line style=very thick, 
        axis x line=middle, 
        axis y line=middle, 
         ymin=-1,ymax=5.99,xmin=-1,xmax=5.99, 
         xlabel=$x$, ylabel=$y$,grid=major 
      ] 
        \addplot [draw=none, pattern=north west lines, pattern color=blue!40, domain=-10:12]
                 {3-3/2*x} \drawge;
        \addplot[very thick, domain=-1:2.5,<->] {3-3/2*x}; 
      \end{axis} 
    \end{tikzpicture} 
    \caption{Problem 4, Part A} 
  \end{figure} 

\end{document}

这里的问题是如何让它与以下设置一起工作：

在此处输入图片描述

\documentclass[dvipsnames]{article}
\usepackage{amsmath,pgfplots,tikz}
\usetikzlibrary{arrows,calc}
\begin{document}

    \begin{tikzpicture}[transform shape,scale=0.6]
    \draw[step=1cm,gray,very thin] (-4,-3) grid (4,5);
    \draw [-latex,thick](-4,0) -- (4,0) node[right] {$x$} coordinate(x axis);
    \foreach \x in {-3,-2,-1,1,2,3}
             \draw (\x,0.1) -- (\x,-0.1) node [fill=white,below] {$\x$};
    \foreach \y in {-2,-1,1,2,3,4}
             \draw (0.1,\y) -- (-0.1,\y) node [fill=white,left] {$\y$};
    \draw [-latex,thick](0,-3) -- (0,5) node[above] {$y$} coordinate(y axis);
    \node at (-0.25,-0.3375) {0};
    \draw[color=Cerulean,latex-latex,domain=-1.3:4] plot (\x,-3/2*\x+3);
    \filldraw[OrangeRed] (0,3) circle (1.5pt) node[inner sep=2pt,right,fill=white,shift={(0.25,0)}] {$(0,3)$};
    \filldraw[OrangeRed] (2,0) circle (1.5pt) node[inner sep=2pt,right,fill=white,shift={(0.25,0.35)}] {$(2,0)$};
    \end{tikzpicture}
\end{document}

也就是说，我想用与pgfplots上面最后一个例子类似的方式表示不等式的解集。这可能吗？

答案1

\documentclass[dvipsnames]{article}

\usepackage{pgfplots}
\usetikzlibrary{patterns}

\makeatletter
\newcommand{\pgfplotsdrawaxis}{\pgfplots@draw@axis}
\makeatother
\pgfplotsset{only axis on top/.style={axis on top=false, after end axis/.code={
             \pgfplotsset{axis line style=opaque, ticklabel style=opaque, tick style={thick,opaque},
                          grid=none}\pgfplotsdrawaxis}}}

\begin{document}
  \begin{figure}[htpb]
    \centering
    \label{fig:p3:c1}
    \begin{tikzpicture}
      \begin{axis}[only axis on top,
        axis line style=very thick,
        axis x line=middle,
        axis y line=middle,
         ymin=-3,ymax=5,xmin=-4,xmax=4,
         %xlabel=$x$, ylabel=$y$,
         xtick={-4,-3,-2,-1,0,1,2,3,4},
         ytick={-3,-2,-1,0,1,2,3,4,5},
         xticklabels={,-3,-2,-1,0,1,2,3},
         yticklabels={,-2,-1,0,1,2,3,4},
         grid=both,clip=false
      ]        
        \draw[draw=none,pattern=north west lines, pattern color=blue!40](axis cs: -1.3,5)--(axis cs: 
                4,-3)--(axis cs: 4,5)--cycle;
        \addplot[Cerulean,very thick,latex-latex,domain=-1.3:4] plot (\x,-3/2*\x+3);
        \node[font=\small] at (axis cs: 4.25,0) {$x$};
        \node[font=\small] at (axis cs: 0,5.25) {$y$};
        \filldraw[OrangeRed] (axis cs: 0,3) circle (2pt) node[inner 
                sep=2pt,right=3mm,fill=white]
           {$(0,3)$};
       \filldraw[OrangeRed] (axis cs:2,0) circle (2pt) node[inner 
             sep=2pt,fill=white,anchor=south west] at (axis cs: 2.1,0.1) {$(2,0)$};
      \end{axis}
    \end{tikzpicture}
    \caption{Problem 4, Part A}
  \end{figure}

\end{document}

在此处输入图片描述

由于您希望x和y标签突出（我必须手动放置），我不得不使用clip=false这反过来又阻止使用\drawge命令。因此我选择像 Jesse 一样手动填充图案。我还调整了ticks、ticklabels和网格。

答案2

这是一个可行的解决方案。添加一行带有和draw的命令，如下所示。需要来自 tikzlibrary。patternpattern colorpatterns

如果要将坐标（0,3）、（2,0）隐藏在图案线后面，请将下面的绘制线移到代码的最后。

\draw[draw=none,pattern=north west lines, pattern color=blue!40](-1.3,5)--(4,-3)--(4,5)--cycle;

在此处输入图片描述

代码

\documentclass[dvipsnames]{article}
\usepackage[paper size={8cm, 8cm}]{geometry}
\usepackage{amsmath,pgfplots,tikz}
\usetikzlibrary{arrows,calc}
\usetikzlibrary{decorations.pathmorphing,patterns}
\begin{document}

    \begin{tikzpicture}[transform shape,scale=0.6]
    \draw[step=1cm,gray,very thin] (-4,-3) grid (4,5);
    \draw [-latex,thick](-4,0) -- (4,0) node[right] {$x$} coordinate(x axis);
    \foreach \x in {-3,-2,-1,1,2,3}
             \draw (\x,0.1) -- (\x,-0.1) node [fill=white,below] {$\x$};
    \foreach \y in {-2,-1,1,2,3,4}
             \draw (0.1,\y) -- (-0.1,\y) node [fill=white,left] {$\y$};
    \draw [-latex,thick](0,-3) -- (0,5) node[above] {$y$} coordinate(y axis);
    \node at (-0.25,-0.3375) {0};
\draw[draw=none,pattern=north west lines, pattern color=blue!40](-1.3,5)--(4,-3)--(4,5)--cycle;
\draw[color=Cerulean,latex-latex,domain=-1.3:4] plot (\x,-3/2*\x+3);
\filldraw[OrangeRed] (0,3) circle (1.5pt) node[inner sep=2pt,right,fill=white,shift={(0.25,0)}] {$(0,3)$};
    \filldraw[OrangeRed] (2,0) circle (1.5pt) node[inner sep=2pt,right,fill=white,shift={(0.25,0.35)}] {$(2,0)$};
\end{tikzpicture}
\end{document}

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