Storing the log of column data

[alx]

I have data I imported into RStudio from an xls file inside a variable l_poisson and also I have this same data stored within a vector named pois.data. What I would like to do is take the logarithm of my column entries (of the xls file) or of the entries in general (of the vector) and then store this within a new variable called pois.log though it's not working with my code.

pois.log <- log(pois.data$Longueur)

[nirgrahamuk]

if l_poisson is a data.frame containing a column called Longueur, whereas pois_data is a mere vector with the same data as in Longeur then either

pois.log <- log(pois.data)

or

pois.log <- log( l_poisson$Longueur)