При компиляции LaTeX не строит график арктангенса, хотя ошибок не выдает. В чем проблема? Вот код программы
\documentclass[12pt,a4paper]{article}
\usepackage[left=1.5cm,right=1.5cm,top=1.5cm,bottom=1.5cm]{geometry}
\usepackage{amsfonts}
\usepackage{amsmath,latexsym, amssymb}
\usepackage{tikz}
\usepackage{hhline}
\usepackage{booktabs}
\usepackage{longtable}
\usepackage{array}
\usepackage{multirow}
\usepackage{makecell}
\usepackage{pgfplots}
\usepackage{longtable}
\usepackage[russian]{babel}
\usepackage{mathtext}
\usepackage{pgf,tikz}
\usepackage{mathrsfs}
\usepackage{graphicx, wrapfig}
\usepackage[miktex]{gnuplottex}
\usetikzlibrary{arrows}
\usetikzlibrary{calc,intersections,intersections, through,backgrounds}
\begin{document}
\definecolor{cqcqcq}{rgb} {0.7529411764705882,0.7529411764705882,0.7529411764705882}
\begin{tikzpicture}[scale=1.0]
\draw [color=cqcqcq,, xstep=1cm,ystep=1cm] (-6.5,-2.5) grid (6.5,1.5);
\draw[thin,->,color=black] (-7,0) — (7,0) node[anchor=north] {\footnotesize $x$};
\foreach \x in {1} \draw[shift={(\x,0)},color=black] (0pt,2pt) — (0pt,-2pt) node[below] {\footnotesize $\x$};
\draw[shift={(-3.141592653589793,0)},color=black] (0pt,2pt) — (0pt,-2pt) node[below] {\footnotesize $-\pi$};
\draw[shift={(-1.5707963267948966,0)},color=black] (0pt,2pt) — (0pt,-2pt) node[below] {\footnotesize $-\pi/2$};
\draw[shift={(1.5707963267948966,0)},color=black] node[below] {\footnotesize $\pi/2$};
\draw[shift={(3.141592653589793,0)},color=black] (0pt,2pt) — (0pt,-2pt) node[below] {\footnotesize $\pi$};
\draw[thin,->,color=black] (0,-3) — (0,2) node[anchor=east] {\footnotesize $y$};
\foreach \y in {-2} \draw[shift={(0,\y)},color=black] (2pt,0pt) — (-2pt,0pt) node[left] {\footnotesize $\y$};
\draw[shift={(0,-1.5707963267948966)},color=black] (2pt,0pt) — (-2pt,0pt) node[left] {\footnotesize $-\pi/2$};
\draw[shift={(0,1.5707963267948966)},color=black] (2pt,0pt) — (-2pt,0pt) node[left] {\footnotesize $\pi/2$};
\draw[shift={(0,0.7853981633974483)},color=black] (2pt,0pt) — (-2pt,0pt) node[left] {\footnotesize $\pi/4$};
\clip(-6.5,-3.5) rectangle (6.5,2.5);
\draw[thin,dotted,samples=1000,domain=-6.5:6.5] plot[id=atan] function{atan(x)};
\end{tikzpicture}
\end{document}