Maximizing LaTeX Sum Function with Substack: Quick Fix Tips

[tom1985]

Hi guys,

Basically I need to have 2 lines underneath a sum, but when I use the {\ substack} command it makes no difference. Any ideas how I can remedy this?

 

[cristo]

substack works for me. Did you put enough brackets etc. in? I just did this and it works: \sum_{\substack{m=1\\n=0}}
$$\sum_{\substack{m=1\\n=0}}$$

 

[tom1985]

Thanks for the reply.
I seem to have enough brackets. I am inputing:

\begin{equation}
\sum_{\substack{{\bf 1},{\bf 2} \\{\bf 1}\neq{\bf 2}}}
=
\sum^\prime_{{\bf 1},{\bf 2}}
\end{equation}
I get the error message "undefined control sequence" ...

 

[cristo]

$$\sum_{\substack{{\bf 1},{\bf 2} \\{\bf 1}\neq{\bf 2}}} = \sum^\prime_{{\bf 1},{\bf 2}}$$

I don't see anything wrong with that-- it works here and on my editor programme.

Can you find out which control sequence it thinks is undefined? Are you sure the error is for that equation?

 

[tom1985]

Are you using the AMS package?
I just put in \usepackage{ams} or whatever, and the substack worked in the \equation environment, but then went completely mental in the \eqnarray environment- thus I guess I will have to change all of the commands to AMS ones right? Not sure I have the time to do that :(

 

[cristo]

Yea, I am using ams-- in the preamble I've got \usepackage{amsmath} and \usepackage{amssymb}.

substack works in eqnarray for me...

 

[tom1985]

I will give that a try.

Couple of other annoying problems:

My references are printing out but the numbers in the text aren't printing. All i get is [?].

My contents page doesn't want to seem to print out either, it just comes up with a blank page once it has been printed out?

 

[cristo]

I will give that a try.

Couple of other annoying problems:

My references are printing out but the numbers in the text aren't printing. All i get is [?].

My contents page doesn't want to seem to print out either, it just comes up with a blank page once it has been printed out?

Make sure you execute the file twice before viewing the pdf document. I don't really know why you have to do this, but I remember when I was given a brief lesson on how to use latex, the instructor said it was important to execute twice before viewing.

 

[tom1985]

What programs do you guys use to draw figures to insert into LaTeX?
I only have crappy "paint" - not sure that will cut it.

 

[AlephZero]

Make sure you execute the file twice before viewing the pdf document. I don't really know why you have to do this, but I remember when I was given a brief lesson on how to use latex, the instructor said it was important to execute twice before viewing.

The first time through it writes a file containing the reference numbers. The second time, it reads the file before it formats the document, so it knows what numbers to use.

Strictly speaking you may need more than 2 passes, because inserting the numbers could change the pagination, so the numbers would be wrong.

If you have the program "texify" it does all the multiple pass stuff automatically.

What programs do you guys use to draw figures to insert into LaTeX?

Anything that will generate images in .eps format will do nicely.

For simple diagrams, \usepackage{xy}, or \begin{picture} ... \end{picture}, can do the whole job in LaTeX.

 

[cristo]

The first time through it writes a file containing the reference numbers. The second time, it reads the file before it formats the document, so it knows what numbers to use.

Thanks, that makes sense now!

What programs do you guys use to draw figures to insert into LaTeX?
I only have crappy "paint" - not sure that will cut it.

I tend to draw diagrams in powerpoint and then export as a jpg-- OK, it's not all that professional, but it does the job pretty well!