General ⇒ Matrix

[Snoop1990]

In general the argument in an Matrix are centered. Is there a way to have them left orientated ?

Simple example:
$$\begin{matrix} x\\ abc \end{matrix}$$

now the above x is over the b but I like to have the x over the a and but there should not be a gap between abc so they should be in one cell.

[localghost]

As a replacement you can use the array environment. But then you have to give a column type to control the alignment of the single columns.

Code: Select all

\[
  \begin{array}{l} x \\ abc \end{array}
\]

The reason why you should not use $$...$$ for displayed mathematical expressions can be found in l2tabu. You can tweak the behaviour of the array environment with the array package.


Best regards
Thorsten¹

[Stefan Kottwitz]

Hi Snoop1990,

regarding matrices and mathematics in general I recommend to use the amsmath package, see for instance the amsmath user's guide 4.1 Matrices. It provides matrices with different delimiters like (), [], {} and || and with more economical horizontal spacing.

Though the column entries will be centered too here's a small modification for the internal macro \env@matrix. By copying this code to your preamble you will be able to use \matrix, \pmatrix, \bmatrix, \Bmatrix, \vmatrix and \Vmatrix with an optional parameter l,r or c (default) for the alignment:

Code: Select all

\usepackage{amsmath}
...
\makeatletter
\renewcommand*\env@matrix[1][c]{\hskip -\arraycolsep
  \let\@ifnextchar\new@ifnextchar
  \array{*\c@MaxMatrixCols #1}}
\makeatother

For more information with examples you may have a look at Matrices with alignment.

Stefan

[balf]

The mathtools package has a series of matrix*, pmatrix*, ..., environments that admit an optional argument : l, r or c (the default).

B.A.

[Snoop1990]

Thank you very much for your help !