Tables and tabularx

Question

I have the following code:

\begin{tabularx}{1\textwidth}{|c||p{4cm}||p{3cm}|}
\hline
\textsc{\textbf{Nombre}} & \textsc{\textbf{Ancho de banda con compresión}} & \textsc{\textbf{Ancho de banda sin compresion}} \\ \hline
H.261 & 40 Kbits/s & 2 Mbits/s \\ \hline
H.263 & 64 Kbits/s & 583.9 Mbits/s \\ \hline
H.263p & 64 Kbits/s & 583.9 Mbits/s \\ \hline
H.264 & 64 Kbits/s & 960 Mbit/s \\ \hline
\end{tabularx}

My problem is that I don't know why it give me this output:

Why the yellow zone appears?

Thanks in advance.

Answer 1

I can't understand why you use \tabularx if you than not use X column type ... If you like to have table width equal to \textwidth, than exploit tabularx capabilities!

Anyway, see if the following solutions is what you looking for:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[spanish]{babel}
\usepackage{newtxtext,newtxmath}

    \usepackage{makecell,tabularx}
    \renewcommand\theadfont{\bfseries\scshape}
    \usepackage{siunitx}

    \begin{document}
\begin{tabularx}{\textwidth}{|X||X||S[table-format=3.2]@{}X<{Mbits/s}|}
                                    \hline
\thead{Nombre} 
        & \thead{Ancho de banda\\ con compresión} 
                     & \multicolumn{2}{c|}{
                       \thead{Ancho de banda\\ sin compresion}} 
                               \\   \hline
H.261   & 40 Kbits/s &   2   & \\   \hline
H.263   & 64 Kbits/s & 583.9 & \\   \hline
H.263p  & 64 Kbits/s & 583.9 & \\   \hline
H.264   & 64 Kbits/s & 960   & \\   \hline
\end{tabularx}
    \end{document}

In it I stole font issues from Mico answer, employ makecell package for seting column headers and for numbers in the third column use S columns from siunitx.

Alternative solution, as rswponse to Mico comment:

In this case the code is a bit modified:

\documentclass{article}
    \usepackage[utf8]{inputenc}
    \usepackage[spanish]{babel}
    \usepackage{newtxtext,newtxmath}

    \usepackage{makecell,tabularx}
    \renewcommand\theadfont{\bfseries\scshape}
    \usepackage{siunitx}

    \begin{document}
\begin{tabularx}{\textwidth}{|@{\quad}l||
           >{\centering\arraybackslash}X||S[table-format=9.2]@{}l<{Mbits/s\qquad\qquad}|}
                                    \hline
\thead{Nombre}
        & \thead{Ancho de banda\\ con compresión}
                     & \multicolumn{2}{c|}{
                       \thead{Ancho de banda\\ sin compresion}}
                               \\   \hline
H.261   & 40 Kbits/s &   2   & \\   \hline
H.263   & 64 Kbits/s & 583.9 & \\   \hline
H.263p  & 64 Kbits/s & 583.9 & \\   \hline
H.264   & 64 Kbits/s & 960   & \\   \hline
\end{tabularx}
    \end{document}

Answer 2

You ask for a tabular length of \textwidth but do not adpate the size of the column. You could use X to do so. In tabularx, X will expand the column to fit the required size.

For example:

\documentclass{article}
\usepackage{tabularx}
\begin{document}

\begin{tabularx}{1\textwidth}{|X||p{4cm}||p{3cm}|}
\hline
\textsc{\textbf{Nombre}} & \textsc{\textbf{Ancho de banda con compresión}} & \textsc{\textbf{Ancho de banda sin compresion}} \\ \hline
H.261 & 40 Kbits/s & 2 Mbits/s \\ \hline
H.263 & 64 Kbits/s & 583.9 Mbits/s \\ \hline
H.263p & 64 Kbits/s & 583.9 Mbits/s \\ \hline
H.264 & 64 Kbits/s & 960 Mbit/s \\ \hline
\end{tabularx}
\end{document}

Output:

Answer 3

In addition to providing at least one type-X column in a tabularx environment, you should also

• use a font family that actually provides bold-smallcaps glyphs (Computer Modern does not), and

• not use full justification in narrow columns, as doing so will almost certainly create unacceptably large gaps between words; instead, use ragged-right mode in narrow columns

• strive for a more "open" look of the table, by (i) not using any vertical bars, (ii) getting rid of the majority of horizontal lines, and (iii) using the line-drawing macros of the booktabs package for the remaining few horizontal lines.

\documentclass{article}
\usepackage{tabularx}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[spanish]{babel}

% Use a font family that provides bold&smallcaps glyphs
\usepackage{newtxtext,newtxmath}     
\usepackage{booktabs,ragged2e}

% ragged-right version of "p" column type
\newcolumntype{P}[1]{>{\RaggedRight\arraybackslash}p{#1}} 

\begin{document}
\noindent
\begin{tabularx}{1\textwidth}{X P{3cm} P{3cm}}
\toprule
\textsc{\textbf{Nombre}} & 
\textsc{\textbf{Ancho de banda con compresión}} & 
\textsc{\textbf{Ancho de banda sin compresión}} \\
\midrule
H.261 & 40 Kbits/s & 2 Mbits/s \\ 
H.263 & 64 Kbits/s & 583.9 Mbits/s \\ 
H.263p & 64 Kbits/s & 583.9 Mbits/s \\ 
H.264 & 64 Kbits/s & 960 Mbit/s \\ 
\bottomrule
\end{tabularx}
\end{document}