How do we add a matrix to a LaTeX document?
How do we add a matrix to a LaTeX document?
Replay
Ash's answer typesets the matrix inline with the text. A (perhaps) nicer way to do this is to use the smallmatrix
environment in the amsmath
package. Add to the document preamble:
\usepackage{amsmath}
And then you can do:
$M = \begin{smallmatrix} a&b\\ c&d \end{smallmatrix}$
If you want to bracket the matrix you can also do:
$M = \left( \begin{smallmatrix} a&b\\ c&d \end{smallmatrix} \right)$
The amsmath
package also offers the shortcut matrix
environments which default to centered alignment for their columns:
matrix
: unbracketed matrix
pmatrix
: matrix surrounded by parentheses
bmatrix
: matrix surrounded by square brackets
vmatrix
: matrix surrounded by single vertical lines
Vmatrix
: matrix surrounded by double vertical lines
This info is found in "The LaTeX Companion", and the amsmath
manual section 4.
First: if you intend to do math in LaTeX, you SHOULD learn and use AMS LaTeX. The best reference is the Short Math Guide for LaTeX. In this guide, you will learn that there are many different matrix macros available when you use the amsmath
package (e.g., \usepackage{amsmath}
).
To quote the document,
4.4. Matrices The environments
pmatrix
,bmatrix
,Bmatrix
,vmatrix
andVmatrix
have (respectively) ( ), [ ], { }, | |, and || || delimiters built in. There is also amatrix
environment sans delimiters, and anarray
environment that can be used to obtain left alignment or other variations in the column specs. [ed. To produce a matrix with parenthesis around it, use:]
\begin{pmatrix}
\alpha & \beta^{*}\\
\gamma^{*} & \delta
\end{pmatrix}
To produce a small matrix suitable for use in text, there is a
smallmatrix
environment [ed. here was a matrix appropriate for text mode] that comes closer to fitting within a single text line than a normal matrix. This example was produced by
\bigl( \begin{smallmatrix}
a & b\\
c & d
\end{smallmatrix} \bigr)
To produce a row of dots in a matrix spanning a given number of columns, use \hdotsfor. For example,
\hdotsfor{3}
in the second column of a four-column matrix will print a row of dots across the final three columns.Note. The plain TeX form
\matrix{...\cr...\cr}
and the related commands\pmatrix
,\cases
should be avoided in LaTeX (and when theamsmath
package is loaded they are disabled).
Finally, I'd like to mention that, while it is possible to set matrices without AMS LaTeX, just use it. It offers so many benefits that until you get the hang of LaTeX, it's the best single macro package for math.
For a matrix of the form:
M = x y
z w
use the LaTeX code:
$M =
\begin{array}{cc}
x & y \\
z & w \\
\end{array}$
For flexible typesetting of matrices with color, lines and justification done by formatting parameters see An extension to amsmath matrix environments.
$M =
\left[ {\begin{array}{*{20}c}
x & y \\
z & w \\
\end{array} } \right]
$
$M =
\left( {\begin{array}{*{20}c}
x & y \\
z & w \\
\end{array} } \right)
$
$M =
\left| {\begin{array}{*{20}c}
x & y \\
z & w \\
\end{array} } \right|
$