Colleagues,

Several days ago, I wrote to the list about a lengthy delay in startup  
of a a script.  I will start with a brief summary of that email.  I  
have a 10,000 line script of which the final 3000 lines constitute a  
function.  The script contains time-markers (cat(date()) to that I can  
determine how fast it was read.  When I invoke the script from the OS  
("R --slave < Script.R"; similar performance with R 2.6.1 or 2.7.0 on  
a Mac / Linux / Windows), the first 7000 lines were read in 5 seconds,  
then it took 2 minutes to read the remaining 3000 lines.  I inquired  
as to the cause for the lengthy reading of the final 3000 lines.

Subsequently, I whittled the 3000 lines to ~ 1000 (moving 2000 lines  
to smaller functions).  Now the first 9000 lines still reads in ~ 6  
seconds and the final 1000 lines in ~ 15 seconds.  Better but not ideal.

However, I just encountered a new situation that I don't understand.   
The R code is now embedded in a graphical interface built with Real  
Basic.  When I invoke the script in that environment, the first 9000  
lines takes the usual 6 seconds.  But, to my surprise, the final 1000  
lines takes 2 seconds!

There is one major difference in the implementation.  With the GUI,  
the commands are "pushed", i.e., the GUI opens R, then sends a  
continuous stream of code.

Does anyone have any idea as to why the delay should be so different  
in the two settings?

Dennis


Dennis Fisher MD
P < (The "P Less Than" Company)
Phone: 1-866-PLessThan (1-866-753-7784)
Fax: 1-415-564-2220
www.PLessThan.com


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