This README provides information on the file ``snpdata'' used in
ref 2.

Joshua Akey sent me a file containing 25,546 SNPs that provide the raw
data for the analysis in ref 1.  I chose from these SNPs the 8,714
that satisfied various requirements (ref 2, p 1410).  The columns in
the file ``snpdata'' are (from left to right)

1  TSC id: TSC identification number
2  SS id: SS identification number from dbSNP
3  RS id: RS identification number from dbSNP
4  TSC chromosome: chromosome of SNP based on TSC database
5  TSC chromosomal position: chromosome position of SNP based on TSC database
6  dbSNP chromosome: chromosome of SNP based on dbSNP database
7  dbSNP chromosome position: chromosome position of SNP based on dbSNP database
8  Celera: 1 if SNP was derived from this submitter; otherwise 0
9  Kwok: 1 if SNP was derived from this submitter; otherwise 0
10 Motorola: 1 if SNP was derived from this submitter; otherwise 0
11 Orchid: 1 if SNP was derived from this submitter; otherwise 0
12 Sanger: 1 if SNP was derived from this submitter; otherwise 0
13 Wi: 1 if SNP was derived from this submitter; otherwise 0
14 East Asian frequency
15 European American frequency
16 African American frequency
17 East Asian sample size
18 European American sample size
19 African American sample size
20 Informativeness for distinguishing African Americans/European Americans
21 Informativeness for distinguishing African Americans/East Asians
22 Informativeness for distinguishing European Americans/East Asians
23 Informativeness for distinguishing African Americans/European Americans/East Asians

I have abbreviated East Asian by the number 5, African American by 1,
and European American by 2.  These are the same code numbers used for
East Asia, Africa, and Europe in other files relating to ref 2.
Columns 1-13 and 17-19 are identical to Joshua Akey's file.  In his
file columns 14-16 had fewer digits; in checking to be sure that all
allele frequencies represented the quotient of an integer and the
reported sample size, I added more digits to these columns.  Columns
20-23 were computed using the I_n statistic (ref 2, eq 4).

[1] Akey JM, Zhang G, Zhang K, Jin L, Shriver MD (2002) Interrogating
a high-density SNP map for signatures of natural selection. Genome Res
12:1805-1814.

[2] Rosenberg NA, Li LM, Ward R, Pritchard JK (2003) Informativeness
of genetic markers for infernece of ancestry. Am J Hum Genet
73:1402-1422.