[R] to create a new variable based on values in other variables

Yuan Chun Ding ycd|ng @end|ng |rom coh@org
Tue Apr 7 20:34:37 CEST 2020

Hi R users,

I want to create a new variable, Ravg, in data frame tem2 based on values of two other variables m1 and m2.

the condition:

if m1 = 23 and m2 =23 then Ravg =23; 
else if m1 != 23 and m2=23 then Ravg =m1;
else if m1 =23 and m2 !=23 then Ravg=m2;
else Ravg=average of m1 and m2;

the Ravg variable should be  same as  m3 variable in the following small example.

my R code did not generate errors but not generate a new variable.

Ravg <- "rare_allele"
  tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12, 23, 12.5, 5))
  for (r in 1:nrow(tem2)) { 
  if (tem2$m1[r] ==23 & tem2$m2[r] ==23) {
    tem2[[Ravg]][r] ==23} else if(tem2$m1[r] ==23 & tem2$m2[r] !=23){
    tem2[[Ravg]][r] ==tem2$m2[r]} else if (tem2$m1[r] !=23 & tem2$m2[r] ==23) {
    tem2[[Ravg]][r] ==tem2$m1[r]} else {
    tem2[[Ravg]][r] == mean(tem2$m1[r] + tem2$m2[r])}

Thank you,



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