How to get both of between- and within subject correlation?

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1

Hello, I have a simple question just written in the title.

How to get both of between- and within subject correlation?

below is my code.

m.1 ← bf(y1 ~x+(1|subject))
m.2 ← bf(y2 ~ x+ (1|subject))

model ← brm(m.1+m.2)+set_rescor(TRUE),
** data = data,**
** family = gaussian)**

VarCorr(model1)

VarCorr function gave me estimated value and confidence interval for correlation of y1 and y2, but i can’t believe this value represents one of the between- or within- subject correlation.

So, how can i get two different levels of correlation terms?

Thank all you for taking the time to help me

2

You are currently only modeling the residual correlation. To also model the correlation in the subject means of y1 and y2, use:

m.1 ← bf(y1 ~ x + (1 | g | subject))
m.2 ← bf(y2 ~ x + (1 | g | subject))
m <- m.1 + m.2 + set_rescor(TRUE)

Also see the Group-level terms section in ?brmsformula

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3

Thanks for your kind answer!

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