[R] Problem with object inside a function

[Ronaldo Reis Junior]

Hi all,

I have a problem with an object inside a formula in a function that I make.

I create an object named qvartemp. This object is OK, look the levels:

> print(levels(qvartemp))
[1] "baixomedio" "alto"

Now I create a new object with a new formula:
 
> new.form <- as.formula(gsub(qvar,"qvartemp",as.expression(mma$formula)))

Look this new object:

> print(new.form)
Riqueza ~ Biomassa * qvartemp

Now here is the problem, I try to update an existing model (mma) changing the 
formula by the new.form

mmaa <- update(mma,new.form)

But my function is aborted with this message:

Error in eval(expr, envir, enclos) : object "qvartemp" not found

If I create this object qvartemp in R section manually it my function work, 
because it get the object from my workspace (but it is usefull just for 
testing), but my function dont find this object qvartemp created inside the 
function.

If I run all my function line by line without use the function it work, I 
think that is because in this case the object is created in my workspace. But 
when I run a function the object is created only in memory (not in my 
workspece) and in this case update dont find this object.

Anybody can suggest any Idea to fix it? I necessary I send my function and a 
example.

Thanks
Ronaldo
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