http://www.unix.com – Suppose file1.bim Code: 1 rs1 0 0 G A 1 rs3 0 1 A C 2 rs8 0 0 G A 2 rs2 0 0 T C 3 rs10 0 0 0 T 3 rs11 0 0 T 0 (N*6 table, where N is arbitary,in this case 6, where 2nd column is the name of SNP, and the 5th,6th are genotype data, where 0 means missing information) There is another file called file1.ped Code: id1 id1 G A A C G G T C T T NA T id3 id3 G G A A A G T C T T T T id5 id5 G G A A G G T T NA NA T NA this ped file is M*(N*2+2) table, where M is the number of individuals, and N is the number of SNPs. First two columns are ID number, where first column and second co (HowTos)