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Simulates data based on a specified slca model. If the model parameters are not already estimated, they can either be provided by the user or generated randomly.

Usage

# S3 method for class 'slca'
simulate(object, nsim = 500, seed = NULL, parm, nlevel, ...)

Arguments

object

an slca object representing the model from which data will be simulated.

nsim

an integer specifying the number of response observations to simulate. The default is 500.

seed

an integer specifying the random seed for reproducibility. If not provided, results will vary across runs.

parm

a user-specified set of parameters to guide the simulation. This is required if the model has not been previously estimated.

nlevel

an integer or integer vector specifying the number of levels for each manifest item in the model. If a single integer is provided, all manifest items will have the same number of levels. The default is 2.

...

Additional arguments passed to other methods.

Value

A list with the following components:

class

A data.frame containing the assigned latent class for each individual across all latent class variables.

response

A data.frame containing the simulated manifest item responses.

Examples

m1 <- slca(lc1[3] ~ x1 + x2 + x3 + x4 + x5,
              lc2[4] ~ y1 + y2 + y3 + y4 + y5)
sim <- simulate(m1, 1000)
sapply(sim$class, table)
#> $lc1
#> 
#>   1   2   3 
#> 286 289 425 
#> 
#> $lc2
#> 
#>   1   2   3   4 
#>  60  73  72 795 
#> 

# simulate data with defined number of levels of manifest items
m2 <- slca(lc1[3] ~ x1 + x2 + x3 + x4)
sim <- simulate(m2, nlevel = c(3, 3, 3, 3))
d <- sim$response
sapply(d, table)
#>    x1  x2  x3  x4
#> 1 218 198 127 184
#> 2 124 164 195 177
#> 3 158 138 178 139

sim <- simulate(m2, nlevel = c(x1 = 2, x3 = 3, x4 = 4, x5 = 5))
d <- sim$response
sapply(d, table)
#> $x1
#> 
#>   1   2 
#> 335 165 
#> 
#> $x2
#> 
#>   1   2   3 
#> 142 232 126 
#> 
#> $x3
#> 
#>   1   2   3   4 
#> 123 197 107  73 
#> 
#> $x4
#> 
#>   1   2   3   4   5 
#> 156  78  60  95 111 
#> 

# simulate data with user-defined parameters
pi <- rep(1 / 3, 3)
rho <- c(.9, .1, .9, .1, .9, .1, .9, .1,
         .9, .1, .9, .1, .1, .9, .1, .9,
         .1, .9, .1, .9, .1, .9, .1, .9)
par <- c(pi, rho)
m3 <- slca(lc[3] ~ y1 + y2 + y3 + y4)
sim <- simulate(m3, parm = par)
mf <- estimate(m3, sim$response)
param(mf)
#> PI :
#> (lc)
#>   class
#>          1       2       3
#>     0.4031  0.2059  0.3910
#> 
#> RHO :
#> (a)
#>         class
#> response       1       2       3
#>    1(V1)  0.1917  1.0000  0.8665
#>    2      0.8083  0.0000  0.1335
#>    1(V2)  0.1634  0.9934  0.8839
#>    2      0.8366  0.0066  0.1161
#>    1(V3)  0.0934  0.1470  0.7982
#>    2      0.9066  0.8530  0.2018
#>    1(V4)  0.1046  0.0000  0.8794
#>    2      0.8954  1.0000  0.1206
#> 
#>    V1 V2 V3 V4
#> lc y1 y2 y3 y4