How to type “田” with filled upper left and lower right sub-squares?

Question

How to type “田” with filled upper left sub-square and lower right sub-square as a character in LaTeX?

Answer 1

Without using any graphic packages (like tikz or pstricks), you can typeset a checkered box \cbox using \rule and \fbox. Rules take the following arguments:

\rule[<raise>]{<width>}{<height>}

while \fbox has a rule width of \fboxrule and separation of \fboxsep. As such, the following minimal example provides \cbox with a NW/SE checkered box and \cbox* with a NE/SW checkered box. The current box width/height has a default of 1ex, although this can be modified by means of an optional <width> argument \cbox[*][<width>]. xparse provides the starred interface, although it could be done without.

\documentclass{article}%
\usepackage{xspace}% http://ctan.org/pkg/xspace
\usepackage{xparse}% http://ctan.org/pkg/xparse
\NewDocumentCommand{\cbox}{s O{1ex}}{%
  \setlength{\fboxsep}{-\fboxrule}%
  \IfBooleanTF{#1}% Condition on starred/unstarred
    {\frame{\rule{0.5\dimexpr#2}{0.5\dimexpr#2}\rule[0.5\dimexpr#2]{0.5\dimexpr#2}{0.5\dimexpr#2}}}% \mybox*
    {\fbox{\rule[0.5\dimexpr#2]{0.5\dimexpr#2}{0.5\dimexpr#2}\rule{0.5\dimexpr#2}{0.5\dimexpr#2}}}% \mybox
  \xspace% Possible space
}
\begin{document}
\renewcommand{\arraystretch}{1.5}
\begin{tabular}{lc}
  \verb!\cbox!: & \cbox \\
  \verb!\cbox*!: & \cbox* \\
  \verb!\cbox[20pt]!: & \cbox[20pt] \\
  \verb!\cbox*[1.5em]!: & \cbox*[1.5em]
\end{tabular}
\end{document}

Using \setlength{\fboxsep}{-\fboxrule} removes any separation between the box contents the the surrounding/boxed rule. xspace corrects for any missed spacing correction after the control sequence.

Answer 2

You might like my package ytableau, which does this easily by design:

\documentclass{article}
\usepackage{ytableau}
\begin{document}
 \begin{ytableau}
  *(black) & \\
   & *(black)
 \end{ytableau}
 \medskip

 \ytableaushort{ {*(black)} {} , {} {*(black)} }
 \medskip

 \ydiagram[*(black)]{1,1+1} * {2,2}
 \medskip

 \ytableausetup{boxsize = 6pt}
 \ydiagram[*(black)]{1,1+1} * {2,2}
\end{document}

It's supposed to produce Young tableaux in mathematics, but there's no reason not to use it for general box-piling. The syntax for this is very simple.

• You can use the environment form, which is just like any array-like environment, but also takes color specifications set off by a * and with the color in parentheses (anything accepted by xcolor is good).

• There's also a short form, where the rows are lists of cells (possibly enclosed in braces if they are not just single characters) with the same color specification syntax.

• There's also the Young diagram form, which doesn't allow anything in the boxes, but takes an optional argument that is put in every box, which can of course be a color specification. You can give it offsets in each row: 1+1 means "skip one space, then put one box". That's what you wanted for the black box in the second row.

• There's also the "chaining" operation: either the short form or the Young diagram can be followed by a * and then another argument list, which can only be for a Young diagram, possibly with an optional argument. The first diagram (either tableau or diagram) is then piled on top of the successive diagrams with the leftmost ones being on the upper layers. This way, you can construct complex color patterns.

• It also has a \ytableausetup command that changes a few things, in this case, the box size. You'll have to read the manual for the full story there.

The package is on CTAN, and therefore, also in TeX Live and (I think) MikTeX.

Answer 3

I don't see that symbol listed anywhere but since you are in a hurry you could consider drawing it with tikz:

\documentclass[12pt]{article}
\usepackage{tikz}
\begin{document}
Start with text, create the picture
\begin{tikzpicture}
\draw[thick] (0,0)--(0,.5)--(.5,.5)--(.5,0)--cycle;
\filldraw (0,.5)--(.25,.5)--(.25,.25)--(0,.25);
\filldraw (.25,.25)--(.5,.25)--(.5,0)--(.25,0);
\end{tikzpicture}
and then some more text.
\end{document}

By varying the coordinates, you can make the symbol as big or small as you want.