[R] Automatic routine - help

[Monica Palaseanu-Lovejoy]

Hi,

I would like to write a little automatic routine in R, but i am a too 
much of a beginner for that. I will appreciate any help regarding this 
particular problem.

Let’s suppose I have a data.frame with j columns (from 1 to n) and i 
rows (from 1 to p). I would like to write a procedure which reads 
every column j (j from 1 to n) and compare each value with the 
interval [0,1]. If z(i,j) is less than 0, then replace z(i,j) with 0. If z(i,j) 
is greater than 1, then replace z(i,j) with 1. If z(i,j) is inside the 
interval [0,1] then don’t change. In the end I would like to have a 
new data.frame with the new values. 

I am not sure how complicated or long such a procedure might be, 
so I will be very grateful for any help.

Thank you in advance,

Monica