The format is:
List of 8
$ geno : num [1:200, 1:66] 1 3 2 2 1 0 3 1 1 3 ...
..- attr(*, "dimnames")=List of 2
.. ..$ : NULL
.. ..$ : chr [1:66] "M1" "M2" "M3" "M4" ...
$ n.ind : num 200
$ n.mar : num 66
$ segr.type : chr [1:66] "A.H.B" "C.A" "D.B" "C.A" ...
$ segr.type.num: num [1:66] 1 3 2 3 3 2 1 3 2 1 ...
$ input : chr "/home/cristiane/R/x86_64-pc-linux-gnu-library/3.4/onemap/extdata/mapmaker_example_f2.raw"
$ n.phe : num 1
$ pheno : num [1:200, 1] 37.6 36.4 37.2 35.8 37.1 ...
..- attr(*, "dimnames")=List of 2
.. ..$ : NULL
.. ..$ : chr "Trait_1"
- attr(*, "class")= chr [1:2] "onemap" "f2"