Math & Science ⇒ multiple newcommands with matrices inside equation

[kaltsoplyn]

Hello all,

I'm writing a thesis in physics. I need to use the, so called, 3-J, 6-J and 9-J symbols (please feel free to google). Instead of typing in matrices in every equation, I define these commands for the 3-J, 6-J and 9-J symbols, respectively:

Code: Select all

\newcommand{\tj}[9]{ \begin{pmatrix}
  #1 & #2 & #3 \\
  #4 & #5 & #6 
 \end{pmatrix}}

\newcommand{\Gj}[6]{ \begin{Bmatrix}
  #1 & #2 & #3 \\
  #4 & #5 & #6 
 \end{Bmatrix}}

\newcommand{\gj}[9]{ \begin{Bmatrix}
  #1 & #2 & #3 \\
  #4 & #5 & #6 \\
  #7 & #8 & #9
 \end{Bmatrix}}

Each one is working fine on its own inside an equation environment. However, when two of them are present in the same equation, I get an error (unless it is the same command twice).
For example, this does not work:

Code: Select all

\begin{equation}
    \gj{1}{2}{3}{4}{5}{6}{7}{8}{9} \tj{1}{2}{3}{4}{5}{6}
\end{equation}

Any ideas?

[gmedina]

Hi,

there's an inconsistency in the definition of \tj; you declare nine arguments but you are using only six in the definition. Changing

Code: Select all

\newcommand{\tj}[9]{ \begin{pmatrix}
  #1 & #2 & #3 \\
  #4 & #5 & #6 
\end{pmatrix}}

to

Code: Select all

\newcommand{\tj}[6]{ \begin{pmatrix}
  #1 & #2 & #3 \\
  #4 & #5 & #6 
\end{pmatrix}}

solves the problem with the code you provided.

[kaltsoplyn]

hahaha, wasn't this a genuine sample of pure stupidity or what?!?
Poor me, I want to write a thesis in physics, too?
who am I kidding? maybe I should become a surgeon instead...

Anyway, thanks for wasting your time on me. Your answer, obviously, solved the problem.

[localghost]

Now that the problem is solved, please mark the topic as accordingly as described in Section 3 of the Board Rules.


Best regards
Thorsten