Returns a 64 bit regionkey

Returns a 64 bit regionkey

EncodeRegionKey(chrom, startpos, endpos, strand)

Arguments

chrom	Encoded Chromosome (see encode_chrom).
startpos	Start position (zero based).
endpos	End position (startpos + region_length).
strand	Encoded Strand direction (-1 > 2, 0 > 0, +1 > 1)