Verify that column names in a data frame are not already present
Source:R/utilities.R
verify_cols_missing.Rd
In 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
newcols
are 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.