R statistics: problem with simple column vector

Question

I have a problem using data from a tab delimited data file imported with read.delim.

Most of the columns contain numerical data which I need to do a

Answer 1

It is possible that some of your data may not be in numeric format after loading it. Check the structure of the data with str(your.data). If your your desired variables are not numeric you can convert them with data$var1 <- as.numeric(data$var1).