Description of the ancestrymap format. The ancestrymap format
can be used as an input format for genotypic matrices in the functions
pca, lfmm and snmf.
Details
The ancestrymap format has one row for each genotype. Each row has 3
columns: the 1st column is the SNP name, the 2nd column is the sample ID,
the 3rd column is th number of alleles. Genotypes for a given SNP name
are written in consecutive lines. The number of alleles can be the number
of reference alleles or the number of derived alleles. Missing genotypes
are encoded by the value 9.
Here is an example of a genotypic matrix using the
ancestrymap format with 3 individuals and 4 SNPs: