TreeCount
Details
- TreeCount gives the number of subtrees with data matching any pattern on any range of levels in a Tree object.
- TreeCount uses standard level specifications as in TreeLevel :
-
n levels 1 through n{n} level n only{n1,n2} levels n1 through n2
- The default value for levelspec in TreeCount is {0,Infinity }.
- A positive level n+1 consists of all subtrees of tree that are children of subtrees on level n.
- Level 0 corresponds to the root of the tree.
- Level -1 corresponds to the leaves.
- A negative level -(n+1) consists of all subtrees whose children are on levels -1, -2, …, -n, with highest level -n.
- TreeCount traverses subtrees in a left-to-right, depth-first order, with children visited before their parents.
- TreeCount [pattern][tree] is equivalent to TreeCount [tree,pattern].
Examples
open all close allBasic Examples (3)
Count the number of subtrees whose data is an even number:
Count the inner subtrees whose data is an even number:
Use the operator form of TreeCount :
Scope (5)
Count the subtrees whose data is an odd integer:
Count the subtrees at levels 1 and 2 whose data is an odd integer:
Count the leaf subtrees whose data is an odd integer:
Count the inner subtrees whose data is an odd integer:
Use the operator form of TreeCount :
Properties & Relations (4)
TreeCount gives the number of matching subtrees given by TreeCases :
TreeSize [tree] is equivalent to TreeCount [tree,_]:
Count [expr,pattern,levelspec] is equivalent to TreeCount [ExpressionTree [expr,"Subexpressions"],pattern,levelspec]:
Count [expr,pattern,levelspec,Heads True ] is equivalent to TreeCount [ExpressionTree [expr,"Subexpressions",Heads True ],pattern,levelspec] for positive levels:
Possible Issues (1)
TreeCount by default starts at level 1, so does not visit the root:
See Also
Related Guides
History
Text
Wolfram Research (2021), TreeCount, Wolfram Language function, https://reference.wolfram.com/language/ref/TreeCount.html.
CMS
Wolfram Language. 2021. "TreeCount." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/TreeCount.html.
APA
Wolfram Language. (2021). TreeCount. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/TreeCount.html
BibTeX
@misc{reference.wolfram_2025_treecount, author="Wolfram Research", title="{TreeCount}", year="2021", howpublished="\url{https://reference.wolfram.com/language/ref/TreeCount.html}", note=[Accessed: 17-November-2025]}
BibLaTeX
@online{reference.wolfram_2025_treecount, organization={Wolfram Research}, title={TreeCount}, year={2021}, url={https://reference.wolfram.com/language/ref/TreeCount.html}, note=[Accessed: 17-November-2025]}