# R/chcemat_simulate.R In TestGardener: Information Analysis for Test and Rating Scale Data

#### Documented in chcemat_simulate

```chcemat_simulate <- function(index.pop, SfdList) {
#  chceimatSIMULATE generates an Nindex.pop by N matrix of random score index
#  values for N test questions and Nindex.pop values of index.pop
#  located at the score index values in SCRFINE.
#  The probabilities for each question are generated by interpolation
#  over the score values in SCRFINE of the probabilities in the MI
#  columns of matrix Pmati.

nfine   <- 101
n       <- length(SfdList)
indfine <- seq(0,100,len=101)
nindex.pop <- length(index.pop)
SList1 <- SfdList[[1]]
Pmat1  <- SList1\$Pmatfine
scrmin <-   0
scrmax <- 100
if (any(index.pop < scrmin) || any(index.pop > scrmax)) {
stop("Values in index.pop out of score index range.")
}
chceimatmat <- matrix(0,nindex.pop,n)
for (i in 1:n) {
SListi <- SfdList[[i]]
Mi     <- SListi\$M
Pmati  <- SListi\$Pmatfine
for (j in 1:nindex.pop) {
prob = matrix(0,1,Mi)
for (m in 1:Mi) {
prob[m]  <- pracma::interp1(indfine, Pmati[,m], index.pop[j])
}
prob  <- prob/apply(prob, 1, sum)
if (any(prob < 0) || any(prob > 1)) {
print(c(j,i,prob))
stop("prob < 0 || prob > 1")
}
uval <- matrix(rmultinom(1,1,prob),1,Mi)
if (!is.numeric(uval)) {
print(uval)
print(prob)
print(sum(prob)-1)
}
m  <- (1:Mi)[uval==1]
if (m < 1 || m > Mi) {
print(c(j,i,m))
stop("m < 1 || m > Mi")
}
chceimatmat[j,i] <- m
}
}

return(chceimatmat)

}
```

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TestGardener documentation built on May 29, 2024, 3:31 a.m.