Is there a way to have a `pmatrix`

environment from `amsmath`

use non-whitespace delimiters such as a comma? I am mainly asking, because I would like to make a row vector this way. I take it, there are essentially two ways of doing something like that:

```
\documentclass{standalone}
\usepackage{mathtools}
\begin{document}
\begin{gather*}
a = \left(1,2,3\right) \\
b = \begin{pmatrix} 1, & 2, & 3 \end{pmatrix}
\end{gather*}
\end{document}
```

Now, especially the second part does not look too pretty:

## Best Answer

https://tex.stackexchange.com/a/53961/6993 provides one solution. It also reminded me of

`\DeclarePairedDelimiter`

from`mathtools`

:A starred version

`\Vector*`

would precede`\lparen`

and`\rparen`

by`\left`

and`\right`

, respectively.