A veces, en un gráfico es necesario separar áreas para mostrar vívidamente cuáles son los dominios. ¿Existe una manera elegante de crear estas áreas hash usando una instrucción similar a la del rectángulo? ¿Sería posible definir el interior con alguna forma? Y sería fantástico si el hash permitiera automáticamente espacios en los que se necesita sobreimponer la notación (como para x y 1 en mi MWE)... Soy consciente del patrón = líneas noreste, pero esa es demasiado rígida , No puedo controlar la distancia entre las líneas. Mi MWE es un poco detallado, lo siento...
\documentclass{standalone}
\usepackage{pgfplots}
\usetikzlibrary{arrows}
\begin{document}
\resizebox{7.0cm}{!}{
\begin{tikzpicture}[>=triangle 45]% functia PUTERE 2^x
%\clip (-0.5,-0.5) rectangle (4.0,4.0);
% grid
%\draw[step = 0.1cm, gray, ultra thin] (-5.0, -1.0) grid (4.0, 0.0);
%
% HASH lines for y < 0
%
\draw[red, line width=1.00pt] (-5.0, -0.1) -- (-4.9, 0.0);
\draw[red, line width=1.00pt] (-5.0, -0.5) -- (-4.5, 0.0);
\draw[red, line width=1.00pt] (-5.0, -1.0) -- (-4.0, 0.0);
\draw[red, line width=1.00pt] (-4.5, -1.0) -- (-3.5, 0.0);
\draw[red, line width=1.00pt] (-4.0, -1.0) -- (-3.0, 0.0);
\draw[red, line width=1.00pt] (-3.5, -1.0) -- (-2.5, 0.0);
\draw[red, line width=1.00pt] (-3.0, -1.0) -- (-2.0, 0.0);
\draw[red, line width=1.00pt] (-2.5, -1.0) -- (-1.5, 0.0);
\draw[red, line width=1.00pt] (-2.0, -1.0) -- (-1.0, 0.0);
\draw[red, line width=1.00pt] (-1.5, -1.0) -- (-0.5, 0.0);
\draw[red, line width=1.00pt] (-1.0, -1.0) -- (0.0, 0.0);
\draw[red, line width=1.00pt] (-0.5, -1.0) -- (0.5, 0.0);
% gap for x notation
\draw[red, line width=1.00pt] (0.0, -1.0) -- (0.4, -0.6);
\draw[red, line width=1.00pt] (0.7, -0.3) -- (1.0, 0.0);
%
\draw[red, line width=1.00pt] (0.5, -1.0) -- (1.5, 0.0);
\draw[red, line width=1.00pt] (1.0, -1.0) -- (2.0, 0.0);
\draw[red, line width=1.00pt] (1.5, -1.0) -- (2.5, 0.0);
\draw[red, line width=1.00pt] (2.0, -1.0) -- (3.0, 0.0);
\draw[red, line width=1.00pt] (2.5, -1.0) -- (3.5, 0.0);
\draw[red, line width=1.00pt] (3.0, -1.0) -- (4.0, 0.0);
\draw[red, line width=1.00pt] (3.5, -1.0) -- (4.0, -0.5);
\draw[red, line width=1.00pt] (3.9, -1.0) -- (4.0, -0.9);
%
%
\coordinate (OR) at (0.00, 0.00);
\coordinate (LX) at (-5.00, 0.00); % left x
\coordinate (RX) at (4.00, 0.00); % right x
\coordinate (BY) at (0.00, -1.00); % bottom y
\coordinate (TY) at (0.00, 8.00);
%
% axa 0x
%
\draw[->][line width=1.00pt] (LX) -- (RX);
\node[violet] at (3.8,-0.4) {\textbf{\textit{x}}};
%
% axa 0y
%
\draw[->][line width=1.00pt] (BY) -- (TY);
\node[right,violet] at (0.2, 8.0) {{\boldmath$a^{\raisebox{+4.0pt}{$\scriptstyle{x}$}}$}};
\node[right,violet] at (0.1, 7.3) {{\boldmath$(a \,=\, 2)$}};
%
% ORIGINE
% points on the graphic
\filldraw [red] (OR) circle(2pt);
\node[violet] at (-0.2,-0.3) {\textbf{\textit{0}}};
%
% COORDONATE -- numerotare axa Ox POZITIVA
%
\draw[violet,line width=1pt] (0.50, -0.10) -- (0.50, 0.10); % x = 0.5
\node[violet] at (0.50, -0.40) {\textbf{\textit{x}}};
\draw[violet,line width=0.75pt,dotted] (0.50, 0.00) -- (0.50, 1.4142);
\filldraw [violet] (0.50, 1.4142) circle(2pt);
\node[above,violet] at (0.50, 1.4142) {\textbf{\textit{a\textsuperscript{x}}}};
%
\draw[line width=1pt] (1.00, -0.10) -- (1.00, 0.10); % x1
\node at (1.00, -0.40) {$\scriptstyle{1}$};
\draw[line width=1pt] (2.00, -0.10) -- (2.00, 0.10); % x2
\node at (2.00, -0.40) {$\scriptstyle{2}$};
\draw[line width=1pt] (3.00, -0.10) -- (3.00, 0.10); % x3
\node at (3.00, -0.40) {$\scriptstyle{3}$};
%
% COORDONATE -- numerotare axa Ox NEGATIVA
%
\draw[line width=1pt] (-1.00, -0.10) -- (-1.00, 0.10); % -x1
\node at (-1.10, -0.40) {$\scriptstyle{-1}$};
\draw[line width=1pt] (-2.00, -0.10) -- (-2.00, 0.10); % -x2
\node at (-2.10, -0.40) {$\scriptstyle{-2}$};
\draw[line width=1pt] (-3.00, -0.10) -- (-3.00, 0.10); % -x3
\node at (-3.10, -0.40) {$\scriptstyle{-3}$};
\draw[line width=1pt] (-4.00, -0.10) -- (-4.00, 0.10); % -x4
\node at (-4.10, -0.40) {$\scriptstyle{-4}$};
%
%
% COORDONATE -- numerotare axa Oy POZITIVA
%
\draw[line width=1.00pt] (-0.1, 1.00) -- (0.10, 1.00); % y1
\node at (-0.40, 1.00) {$\scriptstyle{1}$};
\draw[line width=1.00pt] (-0.1, 2.00) -- (0.10, 2.00); % y2
\node at (-0.40, 2.00) {$\scriptstyle{2}$};
\draw[line width=1.00pt] (-0.1, 3.00) -- (0.10, 3.00); % y3
\node at (-0.40, 3.00) {$\scriptstyle{3}$};
\draw[line width=1.00pt] (-0.1, 4.00) -- (0.10, 4.00); % y4
\node at (-0.40, 4.00) {$\scriptstyle{4}$};
\draw[line width=1.00pt] (-0.1, 5.00) -- (0.10, 5.00); % y5
\node at (-0.40, 5.00) {$\scriptstyle{5}$};
\draw[line width=1.00pt] (-0.1, 6.00) -- (0.10, 6.00); % y6
\node at (-0.40, 6.00) {$\scriptstyle{6}$};
\draw[line width=1.00pt] (-0.1, 7.00) -- (0.10, 7.00); % y7
\node at (-0.40, 7.00) {$\scriptstyle{7}$};
%
% COORDONATE -- numerotare axa Oy NEGATIVA
%
% GRAFICUL functiei 2^x
%
\draw[violet, line width=1.75pt, domain=-5.00:3.00] plot[smooth](\x, {2^(\x)});
%
% filled circles
%
\filldraw [blue] (0.0,1.0) circle(2pt);
%
\end{tikzpicture}
}
%
\hspace*{1.0cm}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\resizebox{8.0cm}{!}{
\begin{tikzpicture}[>=triangle 45]%functia LOGARITM ln x
% grid
%\draw[step = 0.1cm, gray, ultra thin] (-1.0, 0.0) grid (0.0, 2.0);
%
% HASH lines for x < 0
%
\draw[red, line width=1.00pt] (-1.0, 2.9) -- (-0.9, 3.0);
\draw[red, line width=1.00pt] (-1.0, 2.5) -- (-0.5, 3.0);
\draw[red, line width=1.00pt] (-1.0, 2.0) -- (0.0, 3.0);
\draw[red, line width=1.00pt] (-1.0, 1.5) -- (0.0, 2.5);
\draw[red, line width=1.00pt] (-1.0, 1.0) -- (0.0, 2.0);
% gap for 1
\draw[red, line width=1.00pt] (-1.0, 0.5) -- (-0.5, 1.0);
\draw[red, line width=1.00pt] (-0.3, 1.2) -- (0.0, 1.5);
%
\draw[red, line width=1.00pt] (-1.0, 0.0) -- (0.0, 1.0);
\draw[red, line width=1.00pt] (-1.0, -0.5) -- (0.0, 0.5);
\draw[red, line width=1.00pt] (-1.0, -1.0) -- (0.0, 0.0);
\draw[red, line width=1.00pt] (-1.0, -1.5) -- (0.0, -0.5);
\draw[red, line width=1.00pt] (-1.0, -2.0) -- (0.0, -1.0);
\draw[red, line width=1.00pt] (-1.0, -2.5) -- (0.0, -1.5);
\draw[red, line width=1.00pt] (-1.0, -3.0) -- (0.0, -2.0);
\draw[red, line width=1.00pt] (-1.0, -3.5) -- (0.0, -2.5);
\draw[red, line width=1.00pt] (-1.0, -4.0) -- (0.0, -3.0);
\draw[red, line width=1.00pt] (-1.0, -4.5) -- (0.0, -3.5);
\draw[red, line width=1.00pt] (-1.0, -5.0) -- (0.0, -4.0);
\draw[red, line width=1.00pt] (-1.0, -4.5) -- (0.0, -3.5);
\draw[red, line width=1.00pt] (-1.0, -5.0) -- (0.0, -4.0);
\draw[red, line width=1.00pt] (-0.5, -5.0) -- (0.0, -4.5);
\draw[red, line width=1.00pt] (-0.1, -5.0) -- (0.0, -4.9);
%
% LOGARITM function
%
%\clip (-0.5,-0.5) rectangle (4.0,4.0);
%
% grid, drawn with a step in a specified rectangle
%\draw[step = 0.1cm, gray, ultra thin] (-1.0, -5.0) grid (0.0,3.0);
%
%\draw[step=.5cm,gray,very thin] (-1.4,-1.4) grid (1.4,1.4);
%
%
%\begin{comment}
%
\coordinate (OR) at (0.00, 0.00);
\coordinate (LX) at (-1.00, 0.00);
\coordinate (RX) at (8.00, 0.00);
\coordinate (BY) at (0.00, -5.00);
\coordinate (TY) at (0.00, 3.00);
%
% axa 0x
%
\draw[->][line width=1.00pt] (LX) -- (RX);
\node[blue] at (7.8,-0.4) {\textbf{\textit{x}}};
%
% axa 0y
%
\draw[->][line width=1.00pt] (BY) -- (TY);
\node[right,blue] at (0.2, 2.8) {\textbf{\textit{ln x}}};
%
% ORIGIN
% points on the graphic
\filldraw [red] (OR) circle(2pt);
\node[red] at (0.2,-0.3) {\textbf{\textit{0}}};
%
% COORDONATE -- numerotare axa Ox POZITIVA
%
\draw[line width=1pt] (1.00, -0.10) -- (1.00, 0.10); % x1
\node at (1.00, -0.40) {$\scriptstyle{1}$};
\draw[line width=1pt] (2.00, -0.10) -- (2.00, 0.10); % x2
\node at (2.00, -0.40) {$\scriptstyle{2}$};
\draw[line width=1pt] (3.00, -0.10) -- (3.00, 0.10); % x3
\node at (3.00, -0.40) {$\scriptstyle{3}$};
\draw[line width=1pt] (4.00, -0.10) -- (4.00, 0.10); % x4
\node at (4.00, -0.40) {$\scriptstyle{4}$};
\draw[line width=1pt] (5.00, -0.10) -- (5.00, 0.10); % x5
\node at (5.00, -0.40) {$\scriptstyle{5}$};
\draw[line width=1pt] (6.00, -0.10) -- (6.00, 0.10); % x6
\node at (6.00, -0.40) {$\scriptstyle{6}$};
\draw[line width=1pt] (7.00, -0.10) -- (7.00, 0.10); % x7
\node at (7.00, -0.40) {$\scriptstyle{7}$};
%
% COORDONATE -- numerotare axa Ox NEGATIVA
%
% COORDONATE -- numerotare axa Oy POZITIVA
%
\draw[magenta, line width=1.00pt] (-0.1, 1.00) -- (0.10, 1.00); % y1
\node[magenta] at (-0.40, 1.00) {$1$};
\draw[line width=1.00pt] (-0.1, 2.00) -- (0.10, 2.00); % y2
\node at (-0.40, 2.00) {$\scriptstyle{2}$};
%
% COORDONATE -- numerotare axa Oy NEGATIVA
%
\draw[line width=1.00pt] (-0.1, -1.00) -- (0.10, -1.00); % y1
\node at (-0.40, -1.00) {$\scriptstyle{-1}$};
\draw[line width=1.00pt] (-0.1, -2.00) -- (0.10, -2.00); % y2
\node at (-0.40, -2.00) {$\scriptstyle{-2}$};
\draw[line width=1.00pt] (-0.1, -3.00) -- (0.10, -3.00); % y3
\node at (-0.40, -3.00) {$\scriptstyle{-3}$};
\draw[line width=1.00pt] (-0.1, -4.00) -- (0.10, -4.00); % y4
\node at (-0.40, -4.00) {$\scriptstyle{-4}$};
\draw[line width=1.00pt] (-0.1, -5.00) -- (0.10, -5.00); % y5
\node at (-0.40, -5.00) {$\scriptstyle{-5}$};
%
% COORDINATES for drawing
%
%
\coordinate (EE) at (2.7182, 0.00);
\coordinate (PI) at (3.1415, 0.00);
%
% GRAFICUL functiei LOGARITM
%
\draw[blue, line width=1.75pt, domain=0.01:7.00, samples=500] plot[smooth](\x, {ln(\x)});
%
% filled circles
%
\filldraw [red] (1.00, 0.00) circle(2pt);
%
% punctul e
%
\filldraw [magenta] (EE) circle(2pt);
\node[magenta] at (2.7182, -0.30) {\textbf{\textit{e}}};
\draw[magenta, dotted, line width=1.00pt] (2.7182, 0.00) -- (2.7182, 1.00); % e
\draw[magenta, dotted, line width=1.00pt] (0.00, 1.00) -- (2.7182, 1.00); % e
\filldraw [magenta] (2.7182, 1.00) circle(2pt);
%
\end{tikzpicture}
}
\end{document}
Respuesta1
El siguiente código muestra cómo usar define a patterncon definido por el usuario \hatchthicknessy \hatchdistance. Este patrón fue tomado deusando patrones dentro de formas tikz con sombras caídas
Este patrón se utiliza para fillun nodo rectangular que se dibuja en la capa de fondo:
\begin{scope}[on background layer]
\node[fit={(-5,0) (4,-1)}, inner sep=0pt, Pattern] {};
\end{scope}
El patrón no considera holes, pero puede considerar fill=whitetodos los nodos que deben ser legibles sobre él:
\node[violet,fill=white] at (3.8,-0.4) {\textbf{\textit{x}}};
Su código se ha reducido con la definición del patrón, pero también usando algunos \foreachbucles para dibujar ticks. Y creo que podría reducirse aún más si usaras pgfplotsel que está cargado pero nunca se usa.
El siguiente código muestra solo la figura de la izquierda. El correcto se puede obtener fácilmente aplicando herramientas similares.
\documentclass[border=3mm,tikz]{standalone}
\usepackage{pgfplots}
\usetikzlibrary{arrows,patterns,backgrounds,fit}
\makeatletter
\tikzset{% customization of pattern
% based on <m.wibrow@gm...> - 2013-03-24 07:20:
hatch distance/.store in=\hatchdistance,
hatch distance=5pt,
hatch thickness/.store in=\hatchthickness,
hatch thickness=5pt
}
\pgfdeclarepatternformonly[\hatchdistance,\hatchthickness]{north east hatch}% name
{\pgfqpoint{-1pt}{-1pt}}% below left
{\pgfqpoint{\hatchdistance}{\hatchdistance}}% above right
{\pgfpoint{\hatchdistance-1pt}{\hatchdistance-1pt}}%
{
\pgfsetcolor{\tikz@pattern@color}
\pgfsetlinewidth{\hatchthickness}
\pgfpathmoveto{\pgfqpoint{0pt}{0pt}}
\pgfpathlineto{\pgfqpoint{\hatchdistance}{\hatchdistance}}
\pgfusepath{stroke}
}
\makeatother
\tikzset{Pattern/.style={pattern=north east hatch,
pattern color=red, hatch distance=3mm,
hatch thickness=1pt}}
\begin{document}
%\resizebox{7.0cm}{!}{
\begin{tikzpicture}[>=triangle 45]% functia PUTERE 2^x
%\clip (-0.5,-0.5) rectangle (4.0,4.0);
% grid
%\draw[step = 0.1cm, gray, ultra thin] (-5.0, -1.0) grid (4.0, 0.0);
%
%
\coordinate (OR) at (0.00, 0.00);
\coordinate (LX) at (-5.00, 0.00); % left x
\coordinate (RX) at (4.00, 0.00); % right x
\coordinate (BY) at (0.00, -1.00); % bottom y
\coordinate (TY) at (0.00, 8.00);
%
% axa 0x
%
\draw[->][line width=1.00pt] (LX) -- (RX);
\node[violet,fill=white] at (3.8,-0.4) {\textbf{\textit{x}}};
%
% axa 0y
%
\draw[->][line width=1.00pt] (BY) -- (TY);
\node[right,violet] at (0.2, 8.0) {{\boldmath$a^{\raisebox{+4.0pt}{$\scriptstyle{x}$}}$}};
\node[right,violet] at (0.1, 7.3) {{\boldmath$(a \,=\, 2)$}};
%
% ORIGINE
% points on the graphic
\filldraw [red] (OR) circle(2pt);
\node[violet,fill=white] at (-0.2,-0.3) {\textbf{\textit{0}}};
%
% COORDONATE -- numerotare axa Ox POZITIVA
%
\draw[violet,line width=1pt] (0.50, -0.10) -- (0.50, 0.10); % x = 0.5
\node[violet,fill=white] at (0.50, -0.40) {\textbf{\textit{x}}};
\draw[violet,line width=0.75pt,dotted] (0.50, 0.00) -- (0.50, 1.4142);
\filldraw [violet] (0.50, 1.4142) circle(2pt);
\node[above,violet] at (0.50, 1.4142) {\textbf{\textit{a\textsuperscript{x}}}};
%
\foreach \i in {-4,...,-1,1,2,3}{
\draw[line width=1pt] (1.00*\i, -0.10) -- ++(90:0.20); % x1
\node[fill=white] at (1.00*\i, -0.40) {$\scriptstyle{\i}$};}
%
% COORDONATE -- numerotare axa Oy POZITIVA
%
\foreach \i in {1,...,7}{
\draw[line width=1.00pt] (-0.1, \i) -- ++(0:0.20); % y1
\node at (-0.40, \i) {$\scriptstyle{\i}$};
}
%
% COORDONATE -- numerotare axa Oy NEGATIVA
%
% GRAFICUL functiei 2^x
%
\draw[violet, line width=1.75pt, domain=-5.00:3.00] plot[smooth](\x, {2^(\x)});
%
% filled circles
%
\filldraw [blue] (0.0,1.0) circle(2pt);
%
\begin{scope}[on background layer]
\node[fit={(-5,0) (4,-1)}, inner sep=0pt, Pattern] {};
\end{scope}
\end{tikzpicture}
Actualizar
Gracias a Gonzalo Medina, tenemos una pgfplotsversión para esta figura:
\documentclass[border=3mm,tikz]{standalone}
\usepackage{pgfplots}
\usetikzlibrary{arrows,patterns,backgrounds,fit}
\makeatletter
\tikzset{% customization of pattern
% based on <m.wibrow@gm...> - 2013-03-24 07:20:
hatch distance/.store in=\hatchdistance,
hatch distance=5pt,
hatch thickness/.store in=\hatchthickness,
hatch thickness=5pt
}
\pgfdeclarepatternformonly[\hatchdistance,\hatchthickness]{north east hatch}% name
{\pgfqpoint{-1pt}{-1pt}}% below left
{\pgfqpoint{\hatchdistance}{\hatchdistance}}% above right
{\pgfpoint{\hatchdistance-1pt}{\hatchdistance-1pt}}%
{
\pgfsetcolor{\tikz@pattern@color}
\pgfsetlinewidth{\hatchthickness}
\pgfpathmoveto{\pgfqpoint{0pt}{0pt}}
\pgfpathlineto{\pgfqpoint{\hatchdistance}{\hatchdistance}}
\pgfusepath{stroke}
}
\makeatother
\tikzset{Pattern/.style={pattern=north east hatch,
pattern color=#1, hatch distance=3mm,
hatch thickness=1pt}}
\begin{document}
\begin{tikzpicture}[>=triangle 45]
\begin{axis}[
axis lines=middle,
ymax=8,
ymin=-1,
xmax=3.5,
clip=false,
xtick={-4,-3,...,3},
ytick={1,2,...,8},
x tick label style={fill=white}
]
\addplot[violet, line width=1.75pt, domain=-5.00:3.00] {2^(x)};
\node[violet,fill=white]
at (axis cs:3.8,-0.4) {\textbf{\textit{x}}};
\node[right,violet]
at (axis cs:0.2, 8.0)
{{\boldmath$a^{x}$}};
\node[right,violet]
at (axis cs:0.1, 7.3) {{\boldmath$(a \,=\, 2)$}};
\filldraw[red] (axis cs:0,0) circle(2pt);
\draw[violet,line width=0.75pt,dotted]
(axis cs:0.50, 0.00) -- (axis cs:0.50, 1.4142);
\filldraw[violet] (axis cs:0.50, 1.4142) circle(2pt)
node[above,violet]
at (axis cs:0.50, 1.4142)
{\textbf{\textit{a\textsuperscript{x}}}};
\filldraw[blue] (axis cs:0.0,1.0) circle(2pt);
\begin{scope}[on background layer]
\node[fit={(axis cs:-5,0) (axis cs:3.5,-1.3)}, inner sep=0pt, Pattern=cyan] {};
\end{scope}
\end{axis}
\end{tikzpicture}
\end{document}
que produce:
Respuesta2
Me tomé la libertad de dibujar uno de los ejemplos del mfpicpaquete, que viene con una macro creada precisamente para ese tipo de problemas:
\thatch[<hatchsp>,<angle>][<color>]<closed path>
Rellena cualquier camino cerrado con líneas en <angle>grados, separadas entre sí por una distancia de hatchsp. Otra macro, \hatchwd{}la macro especifica el ancho de esas líneas. También hay otras dos macros de sombreado como variantes de \thatchángulos predefinidos \rhatch(de abajo a la izquierda a arriba a la derecha) y \lhatch(de abajo a la derecha a arriba a la izquierda).
En este ejemplo, todo el trabajo de sombreado se realiza mediante las siguientes instrucciones:
\hatchwd{1pt}
\rhatch[3mm][Cyan]\rect{(\xmin, \ymin), (\xmax, 0)}
El código completo:
\documentclass{scrartcl}
\usepackage{multido, xcolor}
\usepackage[metapost, clip, overlaylabels]{mfpic}
\setlength{\mfpicunit}{1cm}
\opengraphsfile{\jobname}
\begin{document}
\begin{mfpic}[1]{-7}{3.9}{-1.5}{8.9}
% Function
\penwd{1pt}
\fdef{f}{x}{2**x}
\draw[magenta]\function{\xmin, \xmax, 0.05}{f(x)}
% Hatching
\hatchwd{1pt}
\rhatch[3mm][Cyan]\rect{(\xmin, \ymin), (\xmax, 0)}
% Axes and marks
\penwd{.5pt}
\doaxes{xy}
\xmarks{ceiling(\xmin) upto -1}\xmarks{1 upto floor(\xmax)}
\ymarks{ceiling(\ymin) upto -1}\ymarks{2 upto floor(\ymax)}
\pointcolor{red}\point[4pt]{(0, 0)}
\pointcolor{blue}\point[4pt]{(0, 1)}
% Labels
\setrender{\gclear}
\tlpointsep{3pt}
\tlabelrect[][tr](0, 0){$O$}
\tlabelrect[][tc](\xmax, 0){$x$}
\tlabel[cr](0, \ymax){$y$}
\tlpointsep{6pt}
\tlpathsep{1pt}
\multido{\i=\xmin+1}{-\xmin}{\tlabelrect[][tc](\i, 0){$\i$}}
\multido{\i=1+1}{\xmax}{\tlabelrect[][tc](\i, 0){$\i$}}
\multido{\i=1+1}{\ymax}{\tlabel[cr](0, \i){$\i$}}
\tlabelrect[][cr](0, -1){$-1$}
\drawcolor{magenta}
\dashed\lines{(0.5, 0), (0.5, 1.414)}
\tlabel[cr](3, 8){\textcolor{magenta}{$a^x (a=2)$}}
\tlabel[bc](0.5, 1.414){\textcolor{magenta}{$a^x$}}
\tlabelrect[][tc](0.5, 0){\textcolor{magenta}{$x$}}
\end{mfpic}
\closegraphsfile
\end{document}
Para compilar primero con LaTeX (sin importar el motor), luego el .mparchivo resultante con MetaPost y luego el .texarchivo nuevamente con LaTeX.
