[R] Rprintf not updating

[Erik Wright]

Hello all,

I am using Rprintf in a C for loop (from .Call) to print a progress indicator showing the current percent complete. The loop I am doing is an time intensive call to another function.  I have noticed that Rprintf does not print to the R-window until the entire loop has been completed.  When it reaches the end of the loop it suddenly prints 0 percent to 100 percent in a split second.  For less intensive function calls it prints properly while looping.  My question is this:  is there any way to force Rprintf to print to the screen during a loop?

On a related note, how can I show a percent sign in the output?  For example, Rprintf("0%"); only prints a zero.

Thanks!,
Erik