Hi,
I am currently writing an extension for R and have the need to include some C code. If I call the code with a large amount of data then it can take several minutes to complete.
The C code prints out after a certain iteration hence letting the user know it hasn't crashed.
When running in R this generally does not happen and all is printed out at the end once the program has completed successfully.
I am using Rprintf() to print out the required output.
e.g. Something simple which illustrates my point
for(int i=0; i<10000; i++){
#Calculations
if (i%1000==0){
Rprintf("Step %d\n",i)
}
}
All I get during the program is the OS X spinning wheel in R. Is there any way to print out as the program is running?
Thanks,
Rob
C code hanging and printing everything at the end
2 messages · Robert Lowe, Simon Urbanek
On Jan 4, 2011, at 11:41 AM, Robert Lowe wrote:
Hi,
I am currently writing an extension for R and have the need to include some C code. If I call the code with a large amount of data then it can take several minutes to complete.
The C code prints out after a certain iteration hence letting the user know it hasn't crashed.
When running in R this generally does not happen and all is printed out at the end once the program has completed successfully.
I am using Rprintf() to print out the required output.
e.g. Something simple which illustrates my point
for(int i=0; i<10000; i++){
#Calculations
if (i%1000==0){
Rprintf("Step %d\n",i)
}
}
All I get during the program is the OS X spinning wheel in R. Is there any way to print out as the program is running?
You want to add R_CheckUserInterrupt(); so that the system has a chance to run the event loop and thus display the result. But the implication is that you may be interrupted so make sure R controls any memory allocations you have made. Cheers, Simon