[Rd] a != a*1 != a+0 != +a
r.hankin at noc.soton.ac.uk
Mon Feb 4 15:25:49 CET 2008
I am writing a package for multivariate polynomials ('multipols')
using S3 methods.
The package includes a Ops.multipol() function for the
arithmetic methods; I would like
to define some sort of user-specified Boolean option which, if
set, would force results to be simplified as they are produced.
Call this option "trim". Trimming a multipol results in
a smaller array that is more manageable.
Mostly one wants to trim, sometimes not.
Would options() be a good way to manage this?
One issue is the behaviour of unary operators "+" and "-".
If trim is TRUE, then "a" is one thing, but "+a" returns
"trim(a)", which might be different.
Also "1*a" would be different from "a" and "a+0"
Does the List consider this to be Good Practice?
Has anyone got comments?
Uncertainty Analyst and Neutral Theorist,
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
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