error when applying weight function to ins()

[agstone90]

Hi Dr. Rizopoulos,

I am having trouble getting the standard normal density function from your book to work with the DerivSplines and was wondering if I need to adapt it in some way. I am currently using
<

g <- function(u, pow = 0) {
f <- function(t) integrate(function(s) s^pow * dnorm(t - s), 0, t)$value
sapply(u, f)
}
iform_cew<-list(fixed=-1+I(g(time))+
ins(time,knots=3,weight.fun =g)+
I(g(time)*(cov)),
indFixed=1:5,
random=-1+I(g(time))+I(g(time,1)),indRandom=1:2)

corresponding to lme object with code
<

lmefit<-lme(longvar~ns(time,3)+cov,random=~time|ID,
data=data,control=lmeControl(opt="optim"))

Running the model with this derivForm returns an error: "Error in integrate(function(s) s^pow * dnorm(t - s), 0, t) :
evaluation of function gave a result of wrong length
In addition: Warning messages:
1: In s^pow :
longer object length is not a multiple of shorter object length
2: In s^pow * dnorm(t - s) :
longer object length is not a multiple of shorter object length"

I haven't been able to find any sample syntax for applying weighting functions to splines for JM and would appreciate any guidance. Thank you!