How to create slant line in a table?

Question

I want to split a table in two part as shown below. How do i split a cell so that i can write "Inferred" and "Ground truth" as shown in following picture.

Answer 1

Package slashbox.sty is available from http://mirror.ctan.org/macros/latex/contrib/slashbox, if it is not installed in your system

\documentclass{article}
\usepackage{slashbox,pict2e}
\begin{document}
\begin{tabular}{@{}c|ccc|c@{}}
\backslashbox{\tabular{@{}l@{}}Ground\\truth\endtabular}{Inferred}
  & 1& 2& 3& \\\hline
1 &  &  &  &   \\
2 &  &  &  &   \\
3 &  &  &  &   \\\hline
  &  &  &  & Total
\end{tabular}
\end{document}