How to find the minimum value of a column in R?

Question

I am new in R and I am trying to do something really simple. I had load a txt file with four columns and now I want to get the minimum value of the second column. This is the code that I have:

 ## Choose the directory of the file   setwd("//Users//dkar//Desktop")   ## Read the txt file   data<-read.table("export_v2.txt",sep="",header=T)   str(data)   ##  this command gives me the minimum for all 4 columns!!  a<-apply(data,2,min) 

Actually, if I want to do something like this: min (data(:,2)). But I don't know how to do it in R. Any help?

Answer 1

If you need minimal value for particular column

min(data[,2]) 

Note: R considers NA both the minimum and maximum value so if you have NA's in your column, they return: NA. To remedy, use:

min(data[,2], na.rm=T) 

Answer 2

If you prefer using column names, you could do something like this as an alternative:

min(data$column_name)