Verify that column names in a data frame are not already present
Source:R/utilities.R
verify_cols_missing.RdIn the Recca package, many functions add columns to an existing data frame.
If the incoming data frame already contains columns with the names of new columns to be added,
a name collision could occur, deleting the existing column of data.
This function provides a way to quickly check whether newcols are already present in
.DF.
Arguments
- .DF
the data frame to which
newcolsare to be added- newcols
a single string, a single name, a vector of strings representing the names of new columns to be added to
.DF, or a vector of names of new columns to be added to.DF
Value
NULL. This function should be called for its side effect of checking the validity
of the names of newcols to be added to .DF.
Details
This function terminates execution if a column of .DF will be overwritten
by one of the newcols.
Examples
df <- data.frame(a = c(1,2), b = c(3,4))
verify_cols_missing(df, "d") # Silent. There will be no problem adding column "d".
newcols <- c("c", "d", "a", "b")
if (FALSE) verify_cols_missing(df, newcols) # Error: a and b are already in df.