[R] Doubt about aov and lm function... bug?

[Peter Dalgaard]

Jose Claudio Faria wrote:
> # a) aov
>> av <- aov(Sepal.Length ~ Species, data=iris)
> 
> Error in parse(text = x) :
>   unexpected symbol in "Sepal(Sepal.Length+Species)Length"
> 
>> traceback()
> 13: parse(text = x)
> 12: eval(parse(text = x)[[1]])
> 11: formula(eval(parse(text = x)[[1]]))
> 10: formula.character(object, env = baseenv())
> 9: formula(object, env = baseenv())
> 8: as.formula(frml)
> 7: expand.formula(frml, colnames(data))
> 6: model.matrix.formula(mt, mf, contrasts)

Er, I have

 >  getAnywhere(model.matrix.formula)
no object named 'model.matrix.formula' was found
 > methods(model.matrix)
[1] model.matrix.default model.matrix.lm

Where did your model.matrix.formula come from???

	-p


> 5: model.matrix(mt, mf, contrasts)
> 4: lm(formula = Sepal.Length ~ Species, data = iris, singular.ok = TRUE)
> 3: eval(expr, envir, enclos)
> 2: eval(lmcall, parent.frame())
> 1: aov(Sepal.Length ~ Species, data = iris)
> 
> # b) lm
>> lm1 <- lm(Sepal.Length ~ Sepal.Width, data=iris)
> 
> Error in parse(text = x) :
>   unexpected symbol in "Sepal(Sepal.Length+Sepal.Width)Length"
> 
>> traceback()
> 10: parse(text = x)
> 9: eval(parse(text = x)[[1]])
> 8: formula(eval(parse(text = x)[[1]]))
> 7: formula.character(object, env = baseenv())
> 6: formula(object, env = baseenv())
> 5: as.formula(frml)
> 4: expand.formula(frml, colnames(data))
> 3: model.matrix.formula(mt, mf, contrasts)
> 2: model.matrix(mt, mf, contrasts)
> 1: lm(Sepal.Length ~ Sepal.Width, data = iris)
> 
> HTH,


-- 
    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
   c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
  (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907