DataFrames in R require a single data type per column of data. The same column may not contain both numeric and character data and when that happens, R coerces the column using the sequence shown as follows:
Logical à Integer à Double à Character
What this means is that, if say a column contains numeric (integer or double) values and character strings, R will coerce the column to be a character column. We can see this by using the typeof command:
> typeof(c(1,2,"a")) [1] "character"
A dataset containing the symbol $ in an amount field for instance, would be interpreted as a character column even though the column was intended to be numeric. In such cases, it would be essential to leverage string operations in R to cleanse ...
