AW: AW: [R] built-in Sweave-like documentation in R-2.x

Khamenia, Valery V.Khamenia at biovision-discovery.de
Wed Aug 11 10:07:04 CEST 2004


> An simpler alternative to code would be to allow one to
> eval-chunk-and-step, stepping through chunks, similar to C-c C-n for
> stepping through lines.  Would this solve the basic problem?  3 x (2
> or 3 keystrokes) for 3 chunks.

hm, not really ideal...


> I can't imagine an evaluation which would cross chunks but use only
> part of chunks (this suggests bad programming design to me), but
> perhaps you (or others) have an example of when this functionality
> would be useful?  (i.e. actual regions to eval which cross code-chunk
> boundaries but contain 1 or 2 incomplete code-chunks?).

hm, when?..
The very typical situation for me today is R-code 
with structure like this:

##############################
# Section 1. Loading data 
# sometime execution time is *very* long (up to 5 minuutes with read.table)
# This section have to be executed quite rarely
...

# Section 2. Some initial data preparations and preprocessing
# execution time might be long. This section have to be 
# executed a bit more often then Section 1.
...

# Section 3. Task-oriented part
# execution time might be very long,
# this section is executed very often.
...
##############################

actually the Section 3 motivated me to start this thread.
because it usually consists of many chunk alternations 
and should be reexecuted many times during development.

--
Valery




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