How to decrease the font size of a table in an \input file

Question

I have:

\documentclass[11pt]{article}
\begin{document}
This is the main tex document.
\input{tables}
\end{document}

In the tables.tex file, I only have numerical tables. I want to decrease the size of fonts used in the table, without modifying tables.tex. Is there proper commands that I can enter right before \input{tables}?

FYI, tables.tex looks like:

\begin{table}[htbp]
\caption{table caption}
\begin{tabular}{rr}
$u$   & 0.00  
\end{tabular}
\end{table}

Answer 1

This works for me:

{\renewcommand\normalsize{\tiny}%
\normalsize
\input{tables}}

Answer 2

You can use the etoolbox package to tap into the start of the tabular environment and modify the font size. In the MWE below, the tabular font size is set to \Huge:

\documentclass{article}
\usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
\BeforeBeginEnvironment{tabular}{\Huge}% Adjust tabular font size to \Huge

\begin{filecontents*}{table.tex}
\begin{table}[htbp]
  \centering
  \caption{table caption}
  \begin{tabular}{rr}
    $u$ & 0.00  
  \end{tabular}
\end{table}
\end{filecontents*}

\begin{document}
Here is some dummy text.

\input{table}%

Here is some more dummy text.
\end{document}

As the name states, \BeforeBeginEnvironment{<env>}{<stuff>} command inserts <stuff> before the beginning of the environment <env> - tabular in this case.

---

If you're interested in modifying only the tables that are included using \input, then it would be best to define your own \input command, say \myinput, and combine it with @Boris' answer. Here's an example of how to do just that:

\documentclass{article}

\usepackage{filecontents}% http://ctan.org/pkg/filecontents
\begin{filecontents*}{table.tex}
\begin{table}
  \centering
  \caption{A table included via \texttt{input}}
  \begin{tabular}{rr}
    $u$ & 0.00  
  \end{tabular}
\end{table}
\end{filecontents*}

\newcommand{\myinput}[1]{%
  \begingroup%
  \renewcommand\normalsize{\tiny}% Specify your font modification
  \input{#1}%
  \endgroup%
}
\begin{document}
Here is some dummy text.

\myinput{table}%

Here is some more dummy text.

\begin{table}
  \centering
  \caption{A table in the main document}
  \begin{tabular}{rr}
    $u$ & 0.00  
  \end{tabular}
\end{table}

\end{document}

Grouping within the \myinput{<file>} command (using \begingroup...\endgroup) ensures that the \normalsize redefinition remains local.

Answer 3

In the following example I define a new command \CFTable with one optional argument, which redefines the table and table* environments as defined by the standard document classes; the optional argument will select the font size switch to be applied to the tables (it will not have any effect on the captions); the valid values for the optional argument are tiny, scriptsize, footnotesize, small (default), normalsize, large, Large, LARGE, huge, and Huge:

\RequirePackage{filecontents}
\begin{filecontents*}{testtables.tex}
\begin{table}
  \centering
  \caption{Some test table}
  \begin{tabular}{cc}
  text & text \\
  123 & 234\\
  123 & 234\\
  123 & 234\\
  123 & 234\\
  123 & 234\\
  \end{tabular}
\end{table}
\end{filecontents*}

\documentclass{article}

\makeatletter
\newcommand\CTFont[1][small]{
\renewenvironment{table}
               {\@float{table}\csname#1\endcsname}
               {\end@float}
\renewenvironment{table*}
               {\@dblfloat{table}\csname#1\endcsname}
               {\end@dblfloat}
}
\makeatother
\begin{document}

\begingroup
\CTFont% tables in \small size
\input{testtables}
\endgroup

\begingroup
\CTFont[tiny]% tables in \tiny size
\input{testtables}
\endgroup

\begingroup
\CTFont[Large]% tables in \Large size
\input{testtables}
\endgroup

\end{document}

The filecontents package and the filecontents* environment are only to provide a complete compilable example; you don't need them in your actual code.

With the code above, the change in the font size will only affect the table contents but not the captions; to achieve a simultaneous change to the caption font size, it's enough to load the caption package:

\usepackage{caption}

and change the definition of \CFTable to

\makeatletter
\newcommand\CTFont[1][small]{
\captionsetup[table]{font=#1}
\renewenvironment{table}
               {\@float{table}\csname#1\endcsname}
               {\end@float}
\renewenvironment{table*}
               {\@dblfloat{table}\csname#1\endcsname}
               {\end@dblfloat}
}
\makeatother

now, however, the only valid values for the optional argument are scriptsize, footnotesize, small (default), normalsize, large, and Large.

Answer 4

You don't mention by how much you want to reduce the font's size. Latex gives you four choices -- \small, \footnotesize, \scriptsize, and \tiny -- to reduce the font size below \normalsize. I'll assume that, for the sake of argument, you're looking to employ the size \small, which is generally 1pt smaller than \normalsize.

If you place the following code snippet in your document's preamble

\makeatletter
\renewenvironment{table}%
    \renewcommand\normalsize{\small} % or \footnotesize, \scriptsize, \tiny, as needed
    \@float{table}}
    {\end@float}
\makeatother

no further changes to your code should be necessary. Note that the meaning of \normalsize will be unchanged outside of table environments.

If you want the fontsize-changing command to affect only tables in the tables.tex file, but no other tables, you could just insert the command

\renewcommand\normalsize{\small} % or \footnotesize, \scriptsize, \tiny, as needed

immediately before the \input tables instruction. (Your MWE seems to indicate that these tables are at the end of the document, so there's no need to encase the statements in a pair of braces.)