Converts onemap R object to onemap input file. The input file brings information about the mapping population: First line: cross type, it can be "outcrossing", "f2 intercross", "f2 backcross", "ri self" or "ri sib". Second line: number of individuals, number of markers, presence (1) or absence (0) of chromossome and position of the markers, and number of phenotypes mesured. Third line: Individuals/sample names; Followed lines: marker name, marker type and genotypes. One line for each marker. Final lines: chromossome, position and phenotypes informations. See more about input file format at vignettes.