The format is:
List of 11
$ geno : num [1:200, 1:54] 1 2 1 1 2 2 2 1 1 2 ...
..- attr(*, "dimnames")=List of 2
.. ..$ : chr [1:200] "BC_001" "BC_002" "BC_003" "BC_004" ...
.. ..$ : chr [1:54] "M001" "M002" "M003" "M004" ...
$ n.ind : int 200
$ n.mar : int 54
$ segr.type : chr [1:54] "A.H" "A.H" "A.H" "A.H" ...
$ segr.type.num: num [1:54] 8 8 8 8 8 8 8 8 8 8 ...
$ n.phe : int 0
$ pheno : NULL
$ CHROM : NULL
$ POS : NULL
$ input : chr "simu_example_bc.raw"
$ error : num [1:10800, 1:2] 1 1 1 1 1 ...
..- attr(*, "dimnames")=List of 2
.. ..$ : chr [1:10800] "M001_BC_001" "M002_BC_001" "M003_BC_001" "M004_BC_001" ...
.. ..$ : NULL
- attr(*, "class")= chr [1:2] "onemap" "backcross"