Two questions: Math mode and tree diagrams for probability in LaTeX

Question

I am trying to print a worksheet for the math class I'm teaching and I was wondering if anyone can specifically help me out in two areas.

a) How do I get the output BAL1L2 without the slant?

     $BAL_{1}L_{2}$

b) And is there is an easier code out there to create tree diagrams for probability?

You need to register first to make you have some privileges. — kiss my armpit, Nov 17 '13 at 03:31
It sounds like you need to read a good introduction to math typesetting. I recommend the mathmode document (available via texdoc). For regular text in math mode, load the amsmath package, and use \text{foo}, unless the element has a specific semantics in which case there are other ways. As for your second question, easier than what? There are plenty of examples already on the site: Probability tree using TikZ for Bernoulli experiments? and What is a more efficient way to draw this tree?. — Alan Munn, Nov 17 '13 at 03:32
Welcome to TeX.SX! You can have a look at our starter guide to familiarize yourself further with our format. — Heiko Oberdiek, Nov 17 '13 at 03:45

NictraSavios · Answer 1 · 2013-11-17T07:57:26.080

4

You can use $\mathrm{BAL_{1}L_{2}$ to remove the slant.

The best tree-diagram program out there is pgf-tkiz, but you could also hack out something with dirtree.

More on probability trees with pgf at this link: Example: Probability tree

Some dirtree stuff here: (Semi-)automatic directory-tree in LaTeX

edited Nov 17 '13 at 07:57

answered Nov 17 '13 at 07:50

NictraSavios

1,697

Small (but crucial) typo: should be \mathrm, not mathrm. Also,  is recommended over $ $ . – ChrisS Nov 17 '13 at 07:55
Huh, so I learned something today. I had it backwards, I thought $ $ was the LaTeX one, and  was the old TeX one. Edited. – NictraSavios Nov 17 '13 at 07:59
And, to be fussy, $\mathtrm{BAL}_{1}\mathrm{L}_{2}$ should be preferred. – egreg Nov 17 '13 at 11:02
Too much typing, I'm a c++ programmer at heart haha. – NictraSavios Nov 17 '13 at 13:12

score 1 · Answer 2 · answered Nov 17 '13 at 08:10

A recommended tree with PSTricks.

\documentclass[preview,border=12pt]{standalone}
\usepackage{pst-tree}

\psset{treemode=R,edge=\ncline}

\def\ABCD{%
    \psTree{\Tcircle{A}} 
        \psTree{\Tcircle{B}} 
            \pstree[edge={\ncline[linecolor=red]}]{\Tcircle{C}}{\Tcircle{D}}\taput{\tiny an example}
            \pstree{\Tcircle{D}}{\Tcircle{C}}
        \endpsTree
        \psTree{\Tcircle{C}} 
            \pstree{\Tcircle{B}}{\Tcircle{D}}
            \pstree{\Tcircle{D}}{\Tcircle{B}}
        \endpsTree
        \psTree{\Tcircle{D}} 
            \pstree{\Tcircle{B}}{\Tcircle{C}}
            \pstree{\Tcircle{C}}{\Tcircle{B}}
        \endpsTree
    \endpsTree
}

\def\BACD{%
    \psTree{\Tcircle{B}} 
        \psTree{\Tcircle{A}} 
            \pstree{\Tcircle{C}}{\Tcircle{D}}
            \pstree{\Tcircle{D}}{\Tcircle{C}}
        \endpsTree
        \psTree{\Tcircle{C}} 
            \pstree{\Tcircle{A}}{\Tcircle{D}}
            \pstree{\Tcircle{D}}{\Tcircle{A}}
        \endpsTree
        \psTree{\Tcircle{D}} 
            \pstree{\Tcircle{A}}{\Tcircle{C}}
            \pstree{\Tcircle{C}}{\Tcircle{A}}
        \endpsTree
    \endpsTree
}

\def\CABD{%
    \psTree{\Tcircle{C}} 
        \psTree{\Tcircle{A}} 
            \pstree{\Tcircle{B}}{\Tcircle{D}}
            \pstree{\Tcircle{D}}{\Tcircle{B}}
        \endpsTree
        \psTree{\Tcircle{B}} 
            \pstree{\Tcircle{A}}{\Tcircle{D}}
            \pstree{\Tcircle{D}}{\Tcircle{A}}
        \endpsTree
        \psTree{\Tcircle{D}} 
            \pstree{\Tcircle{A}}{\Tcircle{B}}
            \pstree{\Tcircle{B}}{\Tcircle{A}}
        \endpsTree
    \endpsTree
}

\def\DABC{%
    \psTree{\Tcircle{D}} 
        \psTree{\Tcircle{A}} 
            \pstree{\Tcircle{B}}{\Tcircle{C}}
            \pstree{\Tcircle{C}}{\Tcircle{B}}
        \endpsTree
        \psTree{\Tcircle{B}} 
            \pstree{\Tcircle{A}}{\Tcircle{C}}
            \pstree{\Tcircle{C}}{\Tcircle{A}}
        \endpsTree
        \psTree{\Tcircle{C}} 
            \pstree{\Tcircle{A}}{\Tcircle{B}}
            \pstree{\Tcircle{B}}{\Tcircle{A}}
        \endpsTree
    \endpsTree
}

\begin{document}
\psTree[thislevelsep=0]{\Tn}
    \ABCD
    \BACD
    \CABD
    \DABC
\endpsTree
\end{document}

enter image description here

Two questions: Math mode and tree diagrams for probability in LaTeX

2 Answers2