Re: PRIOR

[Phil Chalmers]

There is no uniform distribution, so you probably want the lower and upper bound options. And you probably want the expbeta distribution rather than the beta. I'm also pretty sure these models aren't identified, so you may want modify the COV and MEAN inputs. 

Phil

On Tue, Jun 21, 2016 at 8:30 AM, Juscelia Dias Mendonça <jusce...@yahoo.com.br> wrote:

Dear Phil,

I am not able to use the uniform                  distributions and beta as priors .
Can you help me?  See how I'm doing:

mirtsynzeropasso2 <- "
F1 = 1-56
F2 = 1-4,6-8,10-14,16-56
MEAN = F1
COV = F1*F1, F1*F2
PRIOR = (1-56, a1, lnorm, 0, .5),(1-4,6-8,10-14,16-56, a2, lnorm, 0, .5),(1-56, d, unif, -3, 3),(1-56, g, beta, 2, 4)"
# create a mirt model
mirtmodelzeropasso2 <- mirt.model(mirtsynzeropasso2)
# or equivelently:
# mirtmodel <- mirt.model(mirtsyn2, itemnames=colnames(dat))
modzeropasso2<- mirt(dados , mirtmodelzeropasso2,itemtype='3PL')
summary(modzeropasso2,rotate='oblimin')              

Thanks!
Juscelia