General ⇒ How do I make a matrix(4x4) with a square bracket

[akira32]

How do I make a matrix(4x4) with a square bracket? Like the picture I attached.

[localghost]

The picture does not show a matrix with a square bracket (box bracket), but with a round bracket (parenthesis) [1]. So, you should make clear which version you want. Both versions can be realised with the amsmath package.

[1] Bracket - Wikipedia, the free encyclopedia


Best regards
Thorsten¹

[FrankZA]

Easy.

Code: Select all

$\left[\begin{array}{cccc}
w1 & w2 & w3 & w4	\\
x1 & x2 & x3 & x4	\\
y1 & y2 & y3 & y4	\\
z1 & z2 & z3 & z4
\end{array}\right]$

You can choose your bracket type by simply changing the symbol after the \left and \right commands.

[localghost]

Easy. [...] You can choose your bracket type by simply changing the symbol after the \left and \right commands.

The amsmath package offers the much easier way with the bmatrix and the pmatrix environment.

Code: Select all

\[
  \begin{bmatrix}
    a_{11} & a_{12} & a_{13} & a_{14} \\
    a_{21} & a_{22} & a_{23} & a_{24} \\
    a_{31} & a_{32} & a_{33} & a_{34} \\
    a_{41} & a_{42} & a_{43} & a_{44}
  \end{bmatrix}
\]

Replace bmatrix with pmatrix where necessary.

[FrankZA]

Using the \left and \right commands allows you to choose different "boundaries". For example when creating a conditional equation:

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$\left|x\right| = \left\{\begin{array}{cl}
    x & \textrm{if}\ x \geq 0\\
    -x & \textrm{if}\ x < 0
\end{array}\right.$

But I suppose that is a completely different problem.

[localghost]

Using the \left and \right commands allows you to choose different "boundaries". For example when creating a conditional equation: [...] But I suppose that is a completely different problem.

For this issue the (preferably to use) amsmath package offers the cases environment.

Code: Select all

\[
  y=
  \begin{cases}
    x & \text{if}\quad y \geq 0 \\
    -x & \text{if}\quad y < 0
  \end{cases}
\]

As you can see, the amsmath package has also a solution. And it's again easier then that from standard LaTeX.

[FrankZA]

Cool, will have to look into it.