This class represents chromosome band annotation data for a
given experiment. The class is responsible for storing the mapping of
band to set of gene IDs located within that band as well as for
representing the tree structured relationship among the bands.
Objects from the Class
Objects should be created using NewChrBandTree or
ChrBandTreeFromGraph.
Slots
toParentGraph:
Object of class "graph"
representing the tree of chromosome bands. Edges in this directed
graph go from child to parent.
toChildGraph:
Object of class "graph". This is
the same as toParentGraph, but with the edge directons
reversed. This is not an ideal implementation due to the
duplication of data, but it provides quick access to parents or
children of a given node.
root:
Object of class "character" giving the
name of the root node. The convention is to use "ORGANISM:<organism>".
level2nodes:
Object of class "list" providing a
mapping of levels in the tree to the set of nodes at that level.
Levels X is defined as the set of nodes with a path length of
X from the root node.
Methods
allGeneIds
Return a vector of gene IDs representing the gene
universe for this ChrBandTree
childrenOf
Return a list with an element for each the
character vector n. Each element is a character vector of
node names of the children of the named element.
geneIds
Return a vector of gene IDs for a single band.
lgeneIds
Return a list of vectors of gene IDs when given more
than one band. The "l" prefix is for list.
parentOf
Return the parents of the specified bands. See
childrenOf for a description of the structure of the return
value.
treeLevels
Return an integer vector identifying the levels of
the tree.
level2nodes(g, level)
Return the nodes in the tree that are at
the level specified by level. The level argument can
be either numeric or character, but should match a level returned by
treeLevels.
Note
Not all known chromosome bands will be represented in a given
instance. The set of bands that will be present is determined by the
available annotation data and the specified gene universe. The
annotation source maps genes to their most specific band. Such bands
and all bands on the path to the root will be represented in the
resulting tree.
Currently there is only support for human and mouse data.