Hi all: I need to conditionally exit from a function, but don't know how. My example below indicates that when x>0, I wish to immediately exit from the function foo. I also with to return a flag value so that I could find out what happend in executing this function. What command I can use to make it happen? Your help and suggestions will be greatly appreciated. Thanks! ====================================================================== ====== =================================== foo<-function (x) { if (x>0) { do something .... } else { # need to exit from this function at this point, and also return a flag value } do something ... } Weicheng Shen, Ph.D. Senior Image Analyst Science Applications International Corporation 1710 SAIC Drive Mail Stop 2-6-9 McLean, VA 22102 (703) 676-4189

You exit from a function in one of two ways, call return, or fall off of the end (you can of course call return as the last line in the function). Functions *always* return a value (it is not always printed). It is the value of the last statement evaluated. So for the function below, if x<0 it returns the string "ouch", otherwise it returns x+10 foo <- function(x) { if(x<0) return("ouch") y<-10 x+y } On Wed, May 21, 2003 at 05:48:01PM -0400, SHEN, WEICHENG . wrote: > > Hi all: > > I need to conditionally exit from a function, but don't know how. My example > below indicates that when x>0, I wish to immediately exit from the function > foo. I also with to return a flag value so that I could find out what > happend in executing this function. What command I can use to make it > happen? Your help and suggestions will be greatly appreciated. Thanks! > > ==================================================================== ======== > =================================== > > foo<-function (x) > { > if (x>0) { > do something .... > } else { > # need to exit from this function at this point, and also > return a flag value > } > do something ... > } > > Weicheng Shen, Ph.D. > Senior Image Analyst > Science Applications International Corporation > 1710 SAIC Drive > Mail Stop 2-6-9 > McLean, VA 22102 > (703) 676-4189 > > _______________________________________________ > Bioconductor mailing list > Bioconductor@stat.math.ethz.ch > https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor -- +--------------------------------------------------------------------- ------+ | Robert Gentleman phone : (617) 632-5250 | | Associate Professor fax: (617) 632-2444 | | Department of Biostatistics office: M1B20 | | Harvard School of Public Health email: rgentlem@jimmy.harvard.edu | +--------------------------------------------------------------------- ------+