Gráfico no LaTeX (pgfplots)

% Remove the `multi` option and the code in between the
% comment bars to achieve the `standalone` default output.
\documentclass[border = {3mm, 3mm, 3mm, 3mm}]{standalone}
\usepackage[utf8]{inputenc}
\usepackage[brazil]{babel}
\usepackage{pgfplots}
\usepackage{siunitx}
\pgfplotsset{compat=1.12}
\pgfkeys{
    /pgf/number format/.cd,
        set thousands separator={\,},
        min exponent for 1000 sep=4,
        }
\begin{document}
\begin{tikzpicture}
    \pgfplotsset{width=0.7\paperwidth,height=0.5\paperwidth,compat=1.12,
        every axis legend/.append style={
        at={(0.95,0.05)},
        anchor=south east}}
    \begin{axis}[
        xlabel = $y_0$ (\si{\meter}),
        ylabel = $t_v$ (\si{\meter}),
        grid=major,
        xmax=,xmin=,
        ymax=,ymin=,
        ]
    \addplot+[mark size=1, color= blue
        ] table [x index = 0, y index = 1] {questao1b.dat};
    \end{axis}
\end{tikzpicture}
\end{document}