Message-ID: <5040121.1242299040354.JavaMail.root@elwamui-hound.atl.sa.earthlink.net>
Date: 2009-05-14T11:04:00Z
From: Peter Flom
Subject: Simulation)
I wrote
As a beginner, I agree .... the for loop is much clearer to me.
Wacek Kusnierczyk <Waclaw.Marcin.Kusnierczyk at idi.ntnu.no> replied
>
>well, that's quite likely. especially given that typical courses in
>programming, afaik, include for looping but not necessarily functional
>stuff -- are you an r beginner, or a programming beginner?
>
Both. My PhD is in psychometrics, and, both in course work and since then
I've learned a good bit of statistics, but very little programming. I've
picked up a little SAS programming over the years, but not much.
But the loop (at least for me) translates into English more directly than the
lapply statement does.
>among the perl packages i have ever downloaded from cran, it's hard to
>find one without a for loop, but it's easy to find one without a map.
>but it's not necessarily because for loops are easier; just that that's
>the way people are typically taught to program.
>
>the structure and interpretation of computer programs (sicp) by abelson
>& sussman, a beautiful cs masterpiece, introduces mapping (lapplying) on
>p. 105, mentions a for-each control abstraction only in an exercise two
>pages later, and does not really discuss for looping as such.
>functional mapping over stateless objects is, in general, *much* easier
>to reason with than procedural looping over stateful objects -- an issue
>a beginner may not be quite aware of, and learning the basic for loop
>stuff without caring about, e.g., concurrent access to shared mutable
>state etc. may indeed make the impression that for loops are easier.
>
>anyway, once you've learned for loops, it's not a bad idea to learn
>lapply. and once you've learned lapply, you'll probably not go back to
>for loops that easily.
>
Would that be a good book for a beginner?
Peter
Peter L. Flom, PhD
Statistical Consultant
www DOT peterflomconsulting DOT com