[R] How to Trace Back the Warning Messages

[Lorenzo Isella]

Dear All,
I modified a script of mine to allow it to work with complex numbers.
I now have some warnings of this kind:

Warning messages:
1: imaginary parts discarded in coercion
2: imaginary parts discarded in coercion
 and so on.

I would like to be able to find out where in the code something  
triggers these messages.
I am asking if there is some tool to help debug an R script (even 
something which allows you to execute only part of a long script and 
monitor which quantities get changed would be very useful).
Kind Regards

Lorenzo