\documentclass[12pt,a4paper]{report}
\usepackage{xcolor}
\usepackage{graphicx}
\usepackage{fixltx2e}
\usepackage{amsmath,amssymb,mathtools}
\usepackage{MnSymbol}
\usepackage{hyperref}
\usepackage{caption}
\usepackage{float}
\usepackage{ulem}
\usepackage{pgfplots}
\usepackage{xepersian}
\DeclareGraphicsExtensions{.pdf,.png,.jpg}
\settextfont{XB Zar}
\setdigitfont{XB Zar}
\definecolor{a}{RGB}{84,109,204}
\defpersianfont\myfont{IranNastaliq}
\newcommand{\myhyperref}[2]{\hyperref[#1]{#2\ref*{#1}}}
\hyphenation{MATLAB}






\begin{document}
\begin{center}
\begin{tikzpicture}
\begin{axis}
[
xlabel ={Time (second)},ylabel ={y(t)},xmin =0 , xmax =2,ymin =-1 ,ymax = 6,   xtick ={0,0.5,...,2},ytick ={-1,0,...,6}, xtick align = outside , ytick align = outside ,minor tick num =4,width  =10cm ,xlabel style = {font =\Large , color = red,at ={ (axis description cs: 0.5 , -0.05) } } 
, ylabel style = {font =\Large , color = red }, yminorgrids , ymajorgrids ,      y grid style = {color =black,thin,dashed},xmajorgrids,xminorgrids,x grid style ={color =black,thick,solid},legend style ={inner xsep = 4mm,inner ysep = 5mm, fill =yellow,draw =blue}
]
\legend{y,dy}

\addplot [line width =1mm , color =blue!70!red , style =solid ]
table[y index =0, x index =3]
{vali.dat};

\addplot[line width =0.5mm, color =red!50!yellow ,style =solid]
table[y index = 1, x index =3]
{vali.dat};


\end{axis}
\end{tikzpicture}

\end{center}
\end{document}