Convert cM/MB to cM

Question

[diviya.smith]

I have a naive question about recombination maps. I need to use the genetic position in cM but I only have the physical position and rate in cM/MB. How do I convert this to a position in cM? I looked at the HapMap recombination maps and the conversion is not directly obvious to me.

Chromosome    Position(bp)    Rate(cM/Mb)    Map(cM)
chr3    61113    2.699484    0.000000
chr3    61495    0.980191    0.001031
chr3    62226    0.854964    0.001748

Using col 2 (bp position) and 3 (cM/MB), I need to derive col 4. Any suggestions?

Answer 1

[diviya.smith]

Actually figured it out -was just looking at the wrong numbers before. To col 3 = (pos - prevpos)* cM/MB. Not sure how to close/ delete this post though.