[R-sig-ME] lme predict function

[HARSHANA KIRIELLA]

 Dear R users,

I apologies in advance if this is really obvious question.
My problem can be best described by the following example. I believe
fm1 and fm2 are equivalent model and the data frame newOrth2 which
mirrors the data frame newOrth contains all the variables in model
fm2. When I try to use the predict function on fm2 I get an error
message:

“Error in model.frame.default(formula = ~QQ + age, data = list(Sex = c(2L,  :

  variable lengths differ (found for 'age')”


Could someone please help and explain to me what I am doing wrong.

#Method 1

fm1 <- lme(distance ~ age, Orthodont, random = ~ age | Subject)

newOrth <- data.frame(Sex = c("Male","Male","Female","Female","Male","Male"),

                      age = c(15, 20, 10, 12, 2, 4),

                      Subject = c("M01","M01","F30","F30","M04","M04"))

predict(fm1,  newOrth, level = 0:1)


#Method 2

QQ<-cbind(1,Orthodont$age)

attr(QQ,"dimnames")<-list(NULL,c("a","W"))

fm2 <- lme( distance ~ age, Orthodont, random = list(Subject=pdSymm(~0+QQ)) )

newOrth2<- data.frame(Sex = c("Male","Male","Female","Female","Male","Male"),

                      age = c(15, 20, 10, 12, 2, 4),

                      QQa = c(1,   1,  1,  1, 1, 1),

                      QQW = c(15, 20, 10, 12, 2, 4),

                      Subject =
c("M01","M01","F30","F30","M04","M04"))

predict(fm2, newOrth2, level = 0:1)


Thanking you all in advance for your help,


Harshana Kiriella