problem with plot

Question

I am having a problem with the following code for generating a plot. I don't know why the first group (Yago) does not include the first entry (the blue one for Sys1) and the second group does not include the last entry (the green one for Sys6). Any suggestions would be appreciated.

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}
    \begin{tikzpicture}
         \begin{axis}[
                major x tick style = transparent,
            xtick=data,
                ybar,
                ymin = 0,
                ymax = 100,
            ymajorgrids = true,
            ylabel = {Offline Time (in min.)},
                xlabel = {Data Set},
                symbolic x coords = {Yago,DBLP},
                ytick = {0,20,40,60,80,100},
                scaled y ticks = false,
            bar width=10pt,
            ]
            \addplot coordinates {(Yago,20) (DBLP,12)};
            \addplot coordinates {(Yago,45) (DBLP,30)};
            \addplot coordinates {(Yago,30) (DBLP,15)};
            \addplot coordinates {(Yago,65) (DBLP,45)};
            \addplot coordinates {(Yago,25) (DBLP,14)};
            \addplot coordinates {(Yago,35) (DBLP,25)};

            \legend{Sys1,Sys2,Sys3,Sys4,Sys5,Sys6}

        \end{axis}
\end{tikzpicture}
\end{document}

Answer 1

The bars are there, but there's not enough room for them to appear: you can use enlarge x limits and/or decrease the bar width:

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}
    \begin{tikzpicture}
         \begin{axis}[
                major x tick style = transparent,
            xtick=data,
                ybar,
                ymin = 0,
                ymax = 100,
            ymajorgrids = true,
            ylabel = {Offline Time (in min.)},
                xlabel = {Data Set},
                symbolic x coords = {Yago,DBLP},
                ytick = {0,20,40,60,80,100},
                scaled y ticks = false,
            bar width=6pt,
            enlarge x limits=0.25,
            ]
            \addplot coordinates {(Yago,20) (DBLP,12)};
            \addplot coordinates {(Yago,45) (DBLP,30)};
            \addplot coordinates {(Yago,30) (DBLP,15)};
            \addplot coordinates {(Yago,65) (DBLP,45)};
            \addplot coordinates {(Yago,25) (DBLP,14)};
            \addplot coordinates {(Yago,35) (DBLP,25)};

            \legend{Sys1,Sys2,Sys3,Sys4,Sys5,Sys6}

        \end{axis}
\end{tikzpicture}
\end{document}