map_func {onemap} | R Documentation |
Functions to convert recombination fractions to distance in cM
(centiMorgans).
haldane(rcmb) kosambi(rcmb)
rcmb |
A recombination fraction between two markers, i.e., a number between
0 and 0.5 . |
Haldane mapping function is defined as
dM = -(1/2) ln(1-2r),
for 0 <=q r <=q 0.5, where r
stands for the recombination fraction
in rcmb
. Kosambi mapping function is
dM = (1/4) ln [(1+2r)/(1-2r),
for 0 <=q r <=q 0.5, where
r
is defined as above.
Both functions return a number with a distance measured in cM
.
Gabriel R A Margarido, gramarga@esalq.usp.br
Haldane, J. B. S. (1919) The combination of linkage values and the calculation of distance between the loci of linked factors. Journal of Genetics 8: 299-309.
Kosambi, D. D. (1944) The estimation of map distance from recombination values. Annuaire of Eugenetics 12: 172-175.
# little difference for small recombination fractions haldane(0.05) kosambi(0.05) # greater difference as recombination fraction increases haldane(0.35) kosambi(0.35)