\documentclass{article} \usepackage[utf8]{inputenc} \usepackage{geometry} [a4paper,lmargin=1.5cm,rmargin=1.5cm,Botton=1.5cm,top=1.75cm] \usepackage{graphicx} \usepackage{wrapfig} \usepackage{color} \usepackage{amsmath} \usepackage[T1]{fontenc} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{cancel} \usepackage[all]{xy} \usepackage{pst-all} \usepackage{fancybox} \usepackage{tikz} \usepackage{gnuplottex} \tikzset{flippedeventlabel/.append style={align=center}} \usetikzlibrary{matrix.skeleton} \usetikzlibrary[shapes,arrows,positioning,fit,backgrounds,intersections,shadows,calc] \usetikzlibrary{positioning} \usetikzlibrary{decorations.text} \usetikzlibrary{decorations.pathmorphing} \usepackage{pgfplots} \pgfplotsset{compat=newest} \usetikzlibrary{datavisualization} \usetikzlibrary[shapes,arrows,positioning,fit,backgrounds,intersections,shadows,calc,datavisualization.formats.functions] \usetikzlibrary{patterns} \usepackage[colorlinks=true,linkcolor=black,citecolor=black,filecolor=magenta,urlcolor=blue]{hyperref} %Paquete de estilo de referencias \urlstyle{same} \title{Una Pequeña Cápsula Del \texttt{Frontend Layer} de \texttt{PGF} En \LaTeX} \author{Nimrod Rodríguez} % Start the document \begin{document} \maketitle \section*{La Suma De Riemann-Stieltjes} El excelente recurso del \texttt{frontend layer} de \texttt{PGF} para programar texto con gráficos.\\ \begin{tikzpicture}[scale =1,domain=-2.5:4, axes/.style= impotant line/.style={very thick},information text/.style={rounded corners, fill=blue,inner sep=2ex}] \draw (1.5,8.5) [xshift=1.85cm,black!90] node [text width=6cm, information text] {\begin{minipage}{2.5in} \bf\color{white} \begin{center} \shadowbox{Riemann-Stieltjes}\\ \end{center} La figura muestra una ilustración de la suma de Riemann-Stieltjes, para el "área bajo la curva" de la función impar cúbica, utilizando el entorno resumido de \texttt{\textbackslash begin \{axis\}} y \texttt{\textbackslash end \{axis\}}, el cual facilita el manejo coordenado al utilizar \texttt {\textbackslash draw} (para agregar etiquetas), y \texttt {\textbackslash fill} (para estilizar el gráfico). \end{minipage}}; \begin{axis}[color=blue] \draw[->, black,dashed] (-2.5,0)--(4.2,0) node[right]{$x$}; \draw[->,black,dashed] (0,-5)--(0,18) node[right]{$y$}; \draw[-] (-2,0)--(-2,-8); \draw[-] (3,0)--(3,27); \addplot[color=magenta,very thick] {x*x*x}; \draw node at (1,65) {$\textcolor{magenta}{f(x)= x^3}$}; \fill[blue] plot[domain=-2:0] (\x,\x * \x * \x )--(-2,0)--(-2,-8)--cycle; \fill[blue] plot[domain=0:2] (\x,\x * \x * \x )--(2,0)--(0,0)--cycle; \fill[green!65!blue!60!black] plot[domain=2:3.5] (\x,\x * \x * \x )--(3.5,0)--(2,0)--(2,8)--cycle; \draw (-0.5,45) node {$\displaystyle\int_{-2}^{\frac{7}{2}} \!\!x^3\mathrm{d}x=\textcolor{green!65!blue!60!black}{\displaystyle\int_{2}^{\frac{7}{2}} \!\!x^3\mathrm{d}x}$}; \draw (-0.5,30) node {$\frac{1}{4}x^4\textcolor{black}{\displaystyle\mid}_{-2}^{\frac{7}{2}}=\textcolor{green!65!blue!60!black}{\frac{1}{4}x^4\textcolor{black}{\displaystyle\mid}_{2}^{\frac{7}{2}}}=\textcolor{green!65!blue!60!black}{33\frac{33}{64}\ unds^2}$}; \draw (-2,0)node[above=0.3cm]{-2}; \draw[-] (-2,1)--(-2,4); \draw (0,0)node[below=0.3cm]{0}; \draw[-] (0,-1)--(0,-4); \draw (2,0)node[below=0.3cm]{2}; \draw[-] (2,-1)--(2,-4); \draw (3.5,0)node[below=0.3cm]{$3\frac{1}{2}$}; \draw[-] (3.5,-1)--(3.5,-4); \draw node at (1.75,3) {\bf\textcolor{white}{\tiny{+}}}; \draw node at (-1.75,-3) {\bf\textcolor{white}{\tiny{-}}}; \end{axis} \end{tikzpicture} \end{document}