[Tex/LaTex] “Misplaced \noalign” error when compiling table made using \tabularx

aligntablestabularxvertical alignment

Can someone help me fix the problem?

\begin{table*}[t]
\centering
\caption{Message header fields (64-bit total)}
\label{table:header}
\begin{tabularx}{\textwidth}{|l|l|l|}
\hline
\multicolumn{1}{|c|}{{\bf Field}} & \multicolumn{1}{c|}{{\bf Length (bits)}} & \multicolumn{1}{c|}{{\bf Description}}                                                                          \\ \hline
Message type                      & 6                                        & UID representing type of message               \\ 
\hline
Priority                          & 3                                        & 0-7: A value representing the urgency of message.  \\ 
\hline
Checksum flag                     & 1                                        & Value . %Set to 0 if no checksum exists \\ 
\hline
state              & 8                                        & UID \\
\hline
Source            & 5                                        & UID                                                                               \\ 
\hline
Source unit number                & 5                                        & UID                                                                                   \\ \hline
Source            & 5                                        & UID                                                                              \\ \hline
Destination       & 5                                        & UID                                                                           \\ 
\hline
Destination         & 5                                        & UID                                                                           \\ \hline
Destination     & 5                                        & UID                                                                          \\ \hline
Application & 16                                       & Representing length                                       \\ 
\hline
\end{tabularx}
\end{table*}

Best Answer

You should change the line

Checksum flag                     & 1                                        & Value is set to 1 if the data is followed by a 16-bit checksum. %Set to 0 if no checksum exists \\

onto

Checksum flag                     & 1                                        & Value is set to 1 if the data is followed by a 16-bit checksum.  \\ %Set to 0 if no checksum exists

In your version \\ is commented and LaTeX has more than 3 columns to align in your tabular.

Related Solutions

[Tex/LaTex] Using tabularx in a custom environment – “misplaced \noalign”

Placing any alignment material (including \hline) in the end clause here doesn't work, I think because of the way tabularx scans ahead for the table material.

Fortunately there is a much easier approach using the environ package. First a simple basic example:

Simple example

\documentclass[12pt,a4paper]{article}

\usepackage{tabularx,environ}

\NewEnviron{simplepredtable}{%
 \begin{tabularx}{0.9\textwidth}{|l| XXX |}
     \hline
       & Heading 1 & Heading 1 & Heading 1 \tabularnewline
     \hline
     \BODY
     \hline
   \end{tabularx}
}

\begin{document}

\begin{simplepredtable}
  Label & Contents & go & here!\tabularnewline
\end{simplepredtable}

\end{document}

The environ package collects the text of the new environment up in a command \BODY which can then be inserted in to some other code. This enables us to write a block that looks like a usual \begin{xtabular}...\end{xtabular}. I have reduced the width of the table, just to avoid overfull boxes.

For your case, very much the same works, and we can pass your caption argument too:

Sample output

\documentclass[12pt,a4paper]{article}

\usepackage[top=2.5cm, left=2.5cm, bottom=2cm, right=2cm]{geometry}

\usepackage{tabularx,environ}

\usepackage[font=footnotesize,labelfont=sc]{caption}
\usepackage{subcaption}

\usepackage[pagewise,modulo]{lineno}

\newcolumntype{C}{>{\centering\arraybackslash}X}

\NewEnviron{predtable}[1]{%
 \par\nolinenumbers%
 \captionof{table}{#1}%
 \begin{tabularx}{\textwidth}{|l| C C C |}
   \hline
   & Heading 1 & Heading 1 & Heading 1 \tabularnewline
   \hline
   \BODY
   \hline
 \end{tabularx}
 \vspace{\partopsep}
 \par\linenumbers%
}

\usepackage{lipsum} %For demonstration text

\begin{document}
\linenumbers

\lipsum[1]

\begin{predtable}{Caption goes here!}
  Label & Contents & go & here!\tabularnewline
\end{predtable}

\lipsum[2]

\end{document}

The lipsum package has been added so we get some text to demonstrate the line numbering, notice the extra \par command. I have also put some vertical space after the table so it doesn't run up against the followin text. However, I would seriously consider wrapping it in say a center environment instead, which would itself provide some vertical spacing.

[Tex/LaTex] Misplaced \noalign error in table, but only when using include{}

The problem is linked to the fact that the LaTeX \input is "non-expandable". Two solutions are proposed in the code, either use the TeX original primitive or first input the file contents in a macro, using, for facility the catchfile package.

\documentclass{article}
\usepackage{colortbl, xcolor}
% Plain old TeX is the best!
\makeatletter\let\expandableinput\@@input\makeatother
% alternative
% \usepackage{catchfile}
% \CatchFileDef{\testtblasmacro}{testtbl}{} % don't forget empty braces

\usepackage{booktabs}
\begin{document}\thispagestyle{empty}
\begin{table}
  \begin{tabular}{lll}
  \toprule
  var1 & var2 & var3 \\
  \midrule
  \expandableinput testtbl.tex
% or 
% \testtblasmacro
  \bottomrule
  \end{tabular}
\end{table}
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Using tabularx in a custom environment – “misplaced \noalign”

[Tex/LaTex] Misplaced \noalign error in table, but only when using include{}

Related Question