An object of class cross. See
read.cross for details.
chr
Optional vector indicating the chromosomes to consider.
This should be a vector of character strings referring to chromosomes
by name; numeric values are converted to strings. Refer to
chromosomes with a preceding - to have all chromosomes but
those considered. A logical (TRUE/FALSE) vector may also be used.
as.table
If TRUE, return the genetic map as a table with
chromosome assignments and marker names. If FALSE, return the map as a
"map" object.
Value
The genetic map: a list with each component containing the marker
positions (in cM) for a chromosome. Each component has class
A or X according to whether it is an autosome or the X
chromosome. The components are either vectors of marker positions or,
for a sex-specific map, 2-row matrices containing the female and male
marker locations. The map itself is given class map.