How to read "paired data" into an R data.table? Using an R list? -

let's have data.table in r:

library("data.table") dt = data.table(x=c("b","b","b","a","a","a"),v=rnorm(6))  > dt        x           v     1: b  0.77399102     2: b  0.71450334     3: b  0.07187842     4: -0.88098815     5: -0.90192891     6:  0.66439642 

i supply vector x field, , vector v field, each 6 items.

however, see supply b 3 times, , a 3 times. key-value pair, i.e.

'b' : '0.77399102', '0.71450334', '0.07187842' 'a' : '-0.88098815', '-0.90192891', '0.66439642' 

in r, 1 implement list, i.e.

pairs = list(b = c('0.77399102', '0.71450334', '0.07187842'),               = c('-0.88098815', '-0.90192891', '0.66439642')) 

i input r list pairs data.table. possible? i'm confused how define x , v fields object. if isn't possible, how 1 this?

use data.table(x = names(pairs), v = pairs). works data.frame.