Otdfbt

Does anyone know how to prevent the branches of a decision tree from converging on each other? This is with Tikz - I've tried tweaking the sibling distance and things like that, but two of the branches at the end converge so that the final values are illegible.

Secondly, does anyone know how to put in a dashed line between the two square "choice" siblings? To indicate an information set.

documentclassarticle
usepackagetikz
tikzset
 choice/.style = shape=rectangle, draw, align=center, color=black, fill=black, font=normalsize,
 chance/.style = shape=circle, draw, align=center, color=black, fill=black, font=normalsize,
 root/.style = choice, font=normalsize, color=black,
 outcome/.style = shape=rectangle, draw=white, align=center, font=tiny, parent anchor=left,


beginfigure[H]
centering
begintikzpicture
 [
 grow = right,
 sibling distance = 6em,
 level distance = 8em,
 edge from parent/.style = draw, -latex,
 every node/.style = font=normalsize,
 sloped
 ]
node [root] 
 child node [outcome, label=right:$30] 
 edge from parent node [below] 
 child node [choice] 
 child node [chance] 
 child node [choice] 
 child node [outcome, label=right:$10]
 child node[outcome, label=right:$100]
 edge from parent node [below] .5
 child node [choice]
 child node [outcome, label=right:$45]
 child node [outcome, label=right:$55]
 edge from parent node [above] .5
 edge from parent node [below] 
 child node [outcome, label=right:$25]
 edge from parent node [above] 
 edge from parent node [above] ;
endtikzpicture
captionSample Decision Tree labelfig: Sample
endfigure

I use yshift option to change the position of the nodes, to avoid overlapping.

I give two choice nodes some names (a and b) and draw a dashed line as usual.

Code:

documentclass[tikz]standalone
tikzset
 choice/.style = shape=rectangle, draw, align=center, color=black, fill=black, font=normalsize,
 chance/.style = shape=circle, draw, align=center, color=black, fill=black, font=normalsize,
 root/.style = choice, font=normalsize, color=black,
 outcome/.style = shape=rectangle, draw=white, align=center, font=tiny, parent anchor=left,


begindocument
begintikzpicture
 [
 grow = right,
 sibling distance = 6em,
 level distance = 8em,
 edge from parent/.style = draw, -latex,
 every node/.style = font=normalsize,
 sloped
 ]
node [root] 
 child node [outcome, label=right:$30] 
 edge from parent node [below] 
 child node [choice] 
 child node [chance] 
 child node [choice] (a) 
 child node [outcome, label=right:$10]
 child node[yshift=-2em,outcome, label=right:$100]
 edge from parent node [below] .5
 child node [choice] (b) 
 child node [yshift=2em,outcome, label=right:$45]
 child node [outcome, label=right:$55]
 edge from parent node [above] .5
 edge from parent node [below] 
 child node [outcome, label=right:$25]
 edge from parent node [above] 
 edge from parent node [above] ;
draw[dashed] (a)--(b);
endtikzpicture
enddocument

I would like to recommend forest, where the syntax is simpler and you do not have to worry about these things.

documentclassarticle
usepackage[edges]forest
tikzset
 choice/.style = shape=rectangle, draw, align=center, color=black, fill=black,
 chance/.style = shape=circle, draw, align=center, color=black, fill=black,
 root/.style = choice, font=normalsize, color=black,
 outcome/.style = shape=rectangle, draw=white, align=center, font=tiny, parent anchor=left,


begindocument
beginforest
for tree=grow'=east,edge=-latex,l+=1cm
[,root
 [,choice
 [$25]
 [,chance
 [,choice,edge label=node[midway,above,sloped].5
 [$55]
 [$45]
 ]
 [,choice,edge label=node[midway,below,sloped].5
 [$100]
 [$10]
 ]
 ]
 ]
 [$30]
]
endforest
enddocument