In my data block, I define a two-dimensional array of matrices called
X. For example:
matrix[4, 12] X[1000, 9];
Each of the 1000 respondents go through 9 trials, and information about these trials are stored in a matrix with 4 rows and 12 columns.
How do I create an object in R that represents what Stan is looking for? If you make a two-dimensional array, you cannot assign an element of it to be a matrix:
> (test <- array(dim = c(3, 4))) [,1] [,2] [,3] [,4] [1,] NA NA NA NA [2,] NA NA NA NA [3,] NA NA NA NA > test[1, 1] <- matrix(1:4, ncol = 2) Error in test[1, 1] <- matrix(1:4, ncol = 2) : number of items to replace is not a multiple of replacement length
How do I make a two-dimensional array filled with matrices in R, in the format that Stan wants?