R data.table assign multiple columns from list output

Question

x = data.table(group=c("a", "b"), x1=c(9, 4), x2=c(2, 7), ss1=c(20, 20), ss2=c(20, 20))
x[,fisher.test(rbind(c(x1, ss1), c(x2, ss2)))[1:3], by=group]

Calculating a fisher.test per group and taking the first three elements of the output generates three named columns for p.value, conf.int and estimate. This is great except it takes only the lower confidence interval and not the upper from the second list item in the Fisher output.

For some reason, I cannot recreate this behaviour when trying to get both the upper and lower CIs.

If you unlist this output it gives all four values, but in a single column V1.

x[,unlist(fisher.test(rbind(c(x1, ss1), c(x2, ss2)))[1:3]), by=group]

Any combination of unlisting, relisting, naming etc. do not seem to give me the required output.

This is a recurring problem for me so would be great to get an answer!

Ian Campbell · Accepted Answer · 2020-06-05 15:16:59Z

3

It's kind of silly, but you could use as.list:

library(data.table)
x[,as.list(unlist(fisher.test(rbind(c(x1, ss1), c(x2, ss2)))[1:3])), by=group]
   group            p.value         conf.int1        conf.int2 estimate.odds ratio
1:     a 0.0877372116511888 0.766153560249588  46.677263221989    4.37927894874589
2:     b  0.507673628580576 0.106483621566036 2.70725328753808   0.577676599291802

answered Jun 5, 2020 at 15:16

Ian Campbell

25.2k14 gold badges43 silver badges62 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

R data.table assign multiple columns from list output

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related