parsing speed
On Tue, May 17, 2005 at 09:50:20AM +0200, Martin Maechler wrote:
"BertG" == Berton Gunter <gunter.berton at gene.com>
on Mon, 16 May 2005 15:20:01 -0700 writes:
BertG> (just my additional $.02) ... and as a general rule
BertG> (subject to numerous exceptions, caveats, etc.)
BertG> 1) it is programming and debugging time that most
BertG> impacts "overall" program execution time; 2) this is
BertG> most strongly impacted by code readability and size
BertG> (the smaller the better); 3) both of which are
BertG> enhanced by modular construction and reuseability,
BertG> which argues for avoiding inline code and using
BertG> separate functions.
BertG> These days, i would argue that most of the time it is
BertG> program clarity and correctness (they are related)
BertG> that is the important issue, not execution speed.
BertG> ... again, subject to exceptions and caveats, etc.
Yes indeed; very good points very well put!
Just to say it again:
**** We strongly recommend not to "inline" your code, but rather
**** program modularly, i.e. call small `utility' functions.
Generally, I fully agree -- modular coding is good, not only in R. However, with regard to execution time, modularisation that involves passing of large amounts of data (100 x 1000 data frames etc.) can cause problems. Best regards, Jan
+- Jan T. Kim -------------------------------------------------------+ | *NEW* email: jtk at cmp.uea.ac.uk | | *NEW* WWW: http://www.cmp.uea.ac.uk/people/jtk | *-----=< hierarchical systems are for files, not for humans >=-----*