# [Tugindia] Diagram message

Nina Mazumdar nina.mazumdar at gmail.com
Mon Jul 21 07:46:32 CEST 2008

On Mon, Jul 21, 2008 at 10:46 AM, Nina Mazumdar <nina.mazumdar at gmail.com> wrote:
> On Sun, Jul 20, 2008 at 10:22 PM, Naveed Shams <nshams40 at yahoo.com> wrote:
>> I want to make the diagram attached with the email message. I am using the following code in LaTeX:
>> \begin{displaymath}
>> \xymatrix{ \wtu $r]^{\lambda} \ar[d]_{\pi} & \wtu' \ar[d]^{\pi'} \\ >> \wtu/\Ga \ar[d]_{\sim} & \wtu'/\Ga' \ar[d]^{\sim}\\ U \[r]& U'} >> \end{displaymath} >> But I am getting the following error message: >> *********************** >> ! Undefined control sequence. >> <argument> ...\COORD@ =\xymatrixCOORD@ \setbox \z >> @ \hbox {\frozen @everymat... >> l.45 \xy@{\save }{\save@ } >> % >> The control sequence at the end of the top line >> of your error message was never \def'ed. >> ************************ >> The problem is that I have used it in another environment successfully and the parameters are pretty much the same in both environments. >> Any ideas? > > Seems like mailman has gobbled up your attachment, possibly it might > have exceeded the size limits allowed for attachments. In the absence > of your code, I could not give a try. However, with 'all' option for > xy package and with a definition for \wtu (I do not know, what it > stands for), it compiled. You have provided \[ ....$ inside the
> matrix which should create a bad math delimiter error (unless you have
> redefined them), so, I changed them to [ ... ].

Further working on this, I found you have missed two right arrow keys. So,
I made the following changes to your matrix which I guess you might
have lost during copy paste operation:

\xymatrix{ \wtu \[r]^{\lambda} \ar[d]_{\pi} & \wtu' \ar[d]^{\pi'} \\

Please change \wtu\[r] to \wtu\ar[r]  in the above line

\wtu/\Ga \ar[d]_{\sim} & \wtu'/\Ga' \ar[d]^{\sim}\\ U \[r]& U'}

Please change  U \[r] to U \ar[r] in the above line

I think, this should be your problem.

Happy TeXing and best regards

--
Nina