r - data.table operations by column name with spaces fails -

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reproducible example

#use iris data set library(data.table) iris  colnames(iris)[3] <- "petal length" iris <- as.data.table(iris)

accessing column without space fine

iris[,petal.width]

however access column name contains space doesn't work

iris[,petal length] iris[,'petal length']

the solution seems be

iris[,iris$'petal length']

comments i'm new data.table. understand there's lot of quirks in data.table; 1 of them? change variable names rid of spaces, i'd prefer not if didn't need to. read previous questions regarding column names - , understand in 2 years since last question updates have allowed - can seen in ease when colname has no spaces.

just use with = false explained under data.table faq points 1.1-1.3 , 2.17:

iris[ ,'petal length', = false]

and make sure read excellent introduction data.table pdf vignette , new html vignettes.

in case, expect (a vector), using [[ more appropriate:

iris[['petal length']]

alternatively, can refer column names if variables in j:

iris[, `petal length`] # note backticks.

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