On Mon, Jun 04, 2001 at 03:48:09PM +0100, Qingchang Zhong wrote:
> I have a problem with arrays in Lyx. Frequently, I need insert vertical
> and horizontal lines into arrays. For example,
> A 0 | 0
> 0 A | 0
> ________
> 0 0 | A
>
> The corresponding latex code is :
>
> \( \left[ \begin{array}{cc|c}
> A & 0 & 0\\
> 0 & A & 0\\
> \hline 0 & 0 & A
> \end{array}\right] \)
>
> I could do this on digital workstation (alpha) before, but now I changed
> to a new computer. When I open the file including such arrays, it
> always adds additional columns in the array like this:
[deleted]
> When compiling it, the following error:
> extra alignment has been changed to ...
> comes out and then it stops.
>
> I think it is because Lyx reads cc|c as four columns when opening the
> file but three columns (which it should be) when compiling.
Yes, the math editor doesn't support vertical (or horizontal) lines in arrays,
so you will need to use ERT (latex mode).
However, the math editor is currently being rewritten, so a future version
of LyX might support lines in arrays.
