Creates transition intensity matrices where elements represent the instantaneous risk of moving between health states.

# S3 method for matrix
qmatrix(x, trans_mat, ...)

# S3 method for data.table
qmatrix(x, trans_mat, ...)

# S3 method for data.frame
qmatrix(x, trans_mat, ...)

## Arguments

x A two-dimensional tabular object containing elements of the transition intensity matrix. A column represents a transition from state $$r$$ to state $$s$$. Each row represents elements of a different transition intensity matrix. See "Details" for more information. Just as in IndivCtstmTrans, a transition matrix describing the states and transitions in a multi-state model. Further arguments passed to or from other methods. Currently unused.

## Value

An array of transition intensity matrices with the third dimension equal to the number of rows in x.

## Details

The object x must only contain non-zero and non-diagonal elements of a transition intensity matrix. The diagonal elements are automatically computed as the negative sum of the other rows.

qmatrix.msm()

## Examples

# 3 state irreversible model
tmat <- rbind(c(NA, 1, 2),
c(NA, NA, 3),
c(NA, NA, NA))
q12 <- c(.8, .7)
q13 <- c(.2, .3)
q23 <- c(1.1, 1.2)
q <- data.frame(q12, q13, q23)
qmat <- qmatrix(q, trans_mat = tmat)
print(qmat)
#> , , 1
#>
#>      [,1] [,2] [,3]
#> [1,]   -1  0.8  0.2
#> [2,]    0 -1.1  1.1
#> [3,]    0  0.0  0.0
#>
#> , , 2
#>
#>      [,1] [,2] [,3]
#> [1,]   -1  0.7  0.3
#> [2,]    0 -1.2  1.2
#> [3,]    0  0.0  0.0
#>
# Matrix exponential of each matrix in array
expmat(qmat)
#> , , 1
#>
#>           [,1]      [,2]      [,3]
#> [1,] 0.3678794 0.2800669 0.3520537
#> [2,] 0.0000000 0.3328711 0.6671289
#> [3,] 0.0000000 0.0000000 1.0000000
#>
#> , , 2
#>
#>           [,1]      [,2]      [,3]
#> [1,] 0.3678794 0.2333983 0.3987223
#> [2,] 0.0000000 0.3011942 0.6988058
#> [3,] 0.0000000 0.0000000 1.0000000
#>