[R] debug vs regular mode

David Winsemius dwinsemius at comcast.net
Fri Aug 10 04:14:39 CEST 2012


On Aug 9, 2012, at 4:56 PM, Zhang, Peng wrote:

> Dear all,
>
> I had a R segmentation fault, and then invoked debug mode and ran step
> by step.
>
> When I reached "terms(Y~X1*X2*...*X16)", I would then have
> "segmentation" fault. However, if I just ran this under regular "R
> interactive" mode, it would be fine though taking long time.
>
> My questions are:
> 1. Is there a known limit of terms for a formula?

I think so. I seem to remember it was something around 500 characters,  
but was raised a couple of years ago.

This is a 2010 extract of a posting by the indomitable Prof Ripley:

"R-devel:
• The previously almost undocumented limit of 256 bytes on a symbol  
name has been raised to 10,000 bytes (a sanity check). Long symbol  
names can sometimes occur when deparsing expressions (for example, in  
model.frame).  "

Found with a MarkMail search with this strategy:

list:org.r-project.r-devel maximum length of formula



Subject:Re: [Rd] model.frame problem

From:Prof Brian Ripley (rip... at stats.ox.ac.uk)

Date:Nov 3, 2010 1:37:50 pm

List:org.r-project.r-devel


> 2. Why does the same function behave differently under debug and  
> regular
> mode?

I cannot help you there.

-- 

David Winsemius, MD
Alameda, CA, USA



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