missing | in multirow

Question

missing | in 3 multirow, dont know what to do :C

\begin{table}[htbp]
    \begin{center}
    \begin{tabular}{|c|c|}
        \hline
        Rango de Tiempo $[s]$ & Viscosidad $[\frac{cm^{2}}{s}]$\\ \hline 
        \multirow{2}{*}{$34 - 115$} & \multirow{2}{*}{$0,224t + \frac{185}{t}$ }\\  \\ \hline
        \multirow{2}{*}{$115 - 215$} & \multirow{2}{*}{$0,223t + 1,55$} \\ \\
        \hline 
        \multirow{2}{*}{> 215} & \multirow{2}{*}{$0,224t + \frac{185}{t}$ } \\\\ \hline         
    \end{tabular}
    \end{center}
    \end{table}

Answer 1

From your comments I conclude that you in fact don't want to use \multirow but search for a way to stretch the rows. For this there's the command \def\arraystretch{xyx}, e. g.:

\begin{table}[htb]
\def\arraystretch{1.5}
\centering
\begin{tabular}{|c|c|}
  \hline
  Rango de Tiempo $[s]$ & Viscosidad $[\frac{cm^{2}}{s}]$ \\ \hline
  34 -- 115             & $0,224t + \frac{185}{t}$        \\ \hline
  115 -- 215            & $0,223t + 1,55$                 \\ \hline
  $> 215$               & $0,224t + \frac{185}{t}$        \\ \hline
\end{tabular}
\end{table}

However, if you want to produce tables in a considered good style, you definitely should \usepackage{booktabs}. An example use for your special case is the following:

\usepackage{booktabs}
…
\begin{table}[htb]
\def\arraystretch{1.5}
\centering
\begin{tabular}{cc}
  \toprule
  Rango de Tiempo $[s]$ & Viscosidad $[\frac{cm^{2}}{s}]$ \\
  \midrule
  34 -- 115             & $0,224t + \frac{185}{t}$        \\
  115 -- 215            & $0,223t + 1,55$                 \\
  $> 215$               & $0,224t + \frac{185}{t}$        \\
  \bottomrule
\end{tabular}
\end{table}

Adjusting the space between the columns can be done with e. g.

\begin{tabular}{c@{\hspace{.6cm}}c}

If you want to align cells by special symbols have a look at the dcolumn or the siunitx package or at related questions like 2746 or 44685.

Answer 2

Echoing @dessert's answer, I don't think you need \multirow at all. I would further like to suggest that (a) you provide a bit more visual structure to the header, (b) use inline-style fractions, and (c) use the macros of the siunitx package to format the units of measurement as well as the numbers that contain , as the decimal marker.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[spanish]{babel}
\usepackage{booktabs}
\usepackage[per-mode=symbol,output-decimal-marker={,}]{siunitx}
\begin{document}
\begin{table}[htbp]
\centering
\begin{tabular}{@{}cc@{}}
\toprule
Rango de Tiempo  & Viscosidad \\{}
[\si{\second}] & [\si{\centi\meter\squared\per\second}]\\ 
\midrule 
34--115  & $\num{0,224}t + 185/t$ \\  
115--215 & $\num{0,223}t + \num{1,55}$  \\
$>215$   & $\num{0,224}t + 185/t$ \\ 
\bottomrule         
\end{tabular}
\end{table}
\end{document}

Answer 3

The problem is that a tabular where vertical rules are used must have all cells specified, either empty or not.

Your “skipped rows” are obtained by \\ \\, which just specifies the first cell in the row as empty. With \\ & \\ also the second cell is specified. The code

\begin{tabular}{|c|c|}
\hline
Rango de Tiempo $[s]$ & Viscosidad $[\frac{cm^{2}}{s}]$\\ \hline
\multirow{2}{*}{$34 - 115$} & \multirow{2}{*}{$0,224t + \frac{185}{t}$ }\\ & \\ \hline
\multirow{2}{*}{$115 - 215$} & \multirow{2}{*}{$0,223t + 1,55$} \\ & \\
\hline
\multirow{2}{*}{> 215} & \multirow{2}{*}{$0,224t + \frac{185}{t}$ } \\ & \\ \hline
\end{tabular}

will produce

that, however, has several small mistakes in it.

1. Symbols for units should be upright and in parentheses, not square brackets that denote dimensions, rather than units (use in Spanish might be different, though).

2. The decimal comma should not be spaced; with \usepackage[spanish]{babel}, the default output of $0.224$ would be 0,224 with no space.

3. You shouldn't use a minus sign for the interval, but an en-dash.

Here are fixes for these issues.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[spanish]{babel}
\usepackage{bigstrut,array}

\begin{document}

\begin{table}[htbp]
\centering
\setlength{\bigstrutjot}{6pt}

\begin{tabular}{|c<{\bigstrut}|c|}
\hline
Rango de Tiempo (s) & Viscosidad (cm$^{2}$/s) \\
\hline
$34$--$115$ & $0.224t + \frac{185}{t}$ \\
\hline
$115$--$215$ & $0.223t + 1.55$ \\
\hline
$>215$ & $0.224t + \frac{185}{t}$ \\
\hline
\end{tabular}

\end{table}

\end{document}

Finally, using siunitx is better (and also booktabs); it's necessary to disable the “quoting” mechanism of babel-spanish that goes into the way also in several other circumstances.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[spanish,es-noquoting]{babel}
\usepackage{booktabs,siunitx}

\sisetup{range-phrase=--,output-decimal-marker={,}}

\begin{document}

\begin{table}[htbp]
\centering

\begin{tabular}{cc}
\toprule
Rango de Tiempo (\si{s}) & Viscosidad (\si{cm^2/s}) \\
\midrule
\numrange{34}{115} & $\num{0.224}t + \frac{\num{185}}{t}$ \\
\addlinespace
\numrange{115}{215} & $\num{0.223}t + \num{1.55}$ \\
\addlinespace
\num{> 215} & $\num{0.224}t + \frac{\num{185}}{t}$ \\
\bottomrule
\end{tabular}

\end{table}

\end{document}