[R] Issue with formula conversion

[David Winsemius]

On Aug 27, 2014, at 12:44 PM, Gang Chen wrote:

> Thanks for the help! However, I just need to get
> 
> pdCompSymm(~1 + Age)

That's not a formula in the R sense of the word. You should do a better job of posting a use case. Perhaps you want an expression?

-- 
David.
> 
> without a tilde (~) at the beginning.
> 
> On Wed, Aug 27, 2014 at 3:34 PM, David Winsemius <dwinsemius at comcast.net> wrote:
>> 
>> On Aug 27, 2014, at 11:19 AM, Gang Chen wrote:
>> 
>>> A random effect formulation for R package nlme is read in as a string
>>> of characters from an input file:
>>> 
>>> ranEff <- "pdCompSymm(~1+Age)"
>>> 
>>> I need to convert 'ranEff' to a formula class. However, as shown below:
>>> 
>>>> as.formula(ranEff)
>>> ~1 + Age
>>> 
>>> the "pdCompSymm" is lost in the conversion. Any solutions?
>> 
>> as.formula(paste("~",ranEff))
>> ~pdCompSymm(~1 + Age)
>> --
>> 
>> David Winsemius
>> Alameda, CA, USA
>> 

David Winsemius
Alameda, CA, USA