[Rd] [EXTERNAL] Re: Fwd: Re: Re: backquotes and term.labels

Therneau, Terry M., Ph.D. therneau at mayo.edu
Thu Mar 8 17:24:49 CET 2018

I looked at the source code you pointed out, and the line
     fr <- fr[attr(terms(fr),"varnames.fixed")]

sure looks to me as though the terms() function has returned an object with a 
varnames.fixed attribute.  Either that or your code has inside knowledge that a reader 
like me won't know.  Given what you said I will guess that terms(x) returns the terms 
attribute of x if that already exists, doing no processing, and you know that fr has 
already been thusly modified?

I have code that uses the variables, term.names, and factors attributes of the terms() 
structure, and all of those have the backticks.  I know the second two will currently 
break the coxme and survival packages, I haven't chased down the effect on the first.

On 03/08/2018 08:42 AM, Ben Bolker wrote:
> Meant to respond to this but forgot.
>   I didn't write a new terms() function  -- I added an attribute to the
> terms() (a vector of the names
> of the constructed model matrix), thus preserving the information at
> the point when it was available.
>    I do agree that it would be preferable to have an upstream fix ...

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