I suggest you aim for a table with an open, easily-accessible look. To that effect, get rid of all vertical rules and most horizontal rules. (Whatever you do, try to avoid creating tables with random-looking widths for horizontal and/or vertical rules.) Use the macros of the booktabs
package to draw the remaining few rules with good spacing.
There's a lot of math material in the table. One can specify the column type as >{$}c<{$}
to get center-set columns whose contents are in math mode automatically; this'll save you a lot of typing of $
symbols.
People also usually do not like to have to crane their necks to read material that's been rotated by 90 degrees. In your case, the table works just as well (and maybe even better...) if you place the word "Subject" in the top line of the table's header.
To color in (or gray) various cells, use the \cellcolor{<color>}
macro of the colortbl package. For available color names, consult the user guide of the xcolor package.
I'll leave it you to fill in the remaining 32 cells.
\documentclass{article}
\usepackage{booktabs,multirow,array}
\usepackage[table]{xcolor} % load both xcolor and colortbl
\begin{document}
\begin{table}
\centering
\begin{tabular}{@{} l*{5}{>{$}c<{$}} @{}}
\toprule
Subject & \multicolumn{5}{c@{}}{$N_{\textnormal{trials}}$}\\
\cmidrule(l){2-6}
& 20 & 60 & 100 & 140 & 180 \\
\midrule
\multirow{2}{*}{AD} & 50.5\pm 3.2 & 50.3\pm4.5 & 52.6\pm4.7 & 51.7\pm5.3 & 51.5\pm 8.4\\
& \cellcolor{lightgray} 74.8\pm4.9 & \\[1ex]
\multirow{2}{*}{AS} & 50.4\pm3.6 & & & \\
& 74.9\pm6.8 & & & & \\
\multirow{2}{*}{NR} & 50.3\pm2.7 & & & \\
& 75.2\pm6.5 & & & & \\
\multirow{2}{*}{RA} & 49.9\pm2.7& & &\\
& 74.8\pm6.6& & & &\\
\midrule
\multirow{2}{*}{Average} & 50.3\pm3.0& & &\\
& 74.9\pm6.2& & & &\\
\bottomrule
\end{tabular}
\end{table}
\end{document}
If you absolutely must employ the "prison look" for tables, but wish to lessen the visual oppressiveness, consider getting rid of the \hline
directives in the body of the tabular
material. And, load the array
package and set \extrarowheight
to a small non-zero length value. :-)
You should also make an effort to give the term "R" ("dispersion value") a consistent appearance. In your code, it shows up in math italics in the table's header but in upright ("Roman") in the body of the table. Do make the appearance of this variable name consistent. In the code below, I show how to make use of the math-italics method. And, while we're talking about consistency, I've made the M
term employ (bold) math italics as well.
Finally, to center some material in a single cell of the first column, use a \multicolumn{1}{|c|}{...}
"wrapper".
\documentclass{article}
\usepackage{array} % for '\extrarowheight' macro
\usepackage{caption} % for '\captionsetup' macro
\usepackage{amstext} % for '\text' macro
\renewcommand{\thetable}{\Roman{table}} % just for this example
\begin{document}
\begin{table}%[h]
\captionsetup{font=bf,skip=0.5\baselineskip}
\setlength{\extrarowheight}{2pt}
\centering
\caption{\boldmath Values of Dispersion Constant ($R$)}
\begin{tabular}{|l|l|l|}
\hline
\multicolumn{1}{|c|}{\textbf{Algorithm}} &
\multicolumn{2}{ c|}{\boldmath\textbf{Dispersion Constant ($R$)}}\\
\hline
& \boldmath $M=16$ & \boldmath $M=32$ \\
\hline
SCA & $R_{\text{SCA}} = 123$ & $R_{\text{SCA}} = 123$ \\ %\hline
MCMA & $R_{\text{MCMA}} = 123$ & $R_{\text{MCMA}} = 123$\\ %\hline
MCMA(Dual Mode) & $R_{\text{MCMA}}$ & $R_{\text{MCMA}}$\\ %\hline
DD-MCMA & $R_{\text{DD-MCMA}} = 123$ & $R_{\text{DD-MCMA}} = 123$\\%\hline
DD-MCMA(Dual Mode) & $R_{\text{DD-MCMA}}$& $R_{\text{DD-MCMA}}$\\
\hline
\end{tabular}
\end{table}
\end{document}
Best Answer
Here is a start for you.
With
\usepackage{rotating
undsidewasytable
and not landscape.Ref. used: https://tex.stackexchange.com/a/133436/124842