does column exist?
On Thu, 19 May 2005 apjaworski at mmm.com wrote:
There may be a simpler way, but this
is.na(match("X", names(df)))
should return TRUE if the column name exists and FALSE otherwise.
Mere syntactic sugar, but "X" %in% names(mydf) is self-documenting.
How do I test if a data.frame has a column named X? exists(o) checks if the object exists or not, I want to test if a data.frame object (df) has a column names(X), something like: exists(df$X)
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595