rstats: Calculating Statistics for the Sampled Matrices

In eRm: Extended Rasch Modeling

Calculating Statistics for the Sampled Matrices

Description

This function is used to calculate user defined statistics for the (original and) sampled matrices. A user defined function has to be provided.

Usage

rstats(RSobj, userfunc, ...)

Arguments

RSobj	object as obtained from using rsampler or rsextrobj
userfunc	a user defined function which performs operations on the (original and) sampled matrices. The first argument in the definition of the user function must be an object of type matrix.
...	further arguments, that are passed to the user function

Value

A list of objects as specified in the user supplied function

Note

The encoded matrices that are contained in the input object RSobj are decoded and passed to the user function in turn. If RSobj is not an object obtained from either rsampler or rsextrobj or no user function is specified an error message is printed. A simple user function, phi.range, is included in the RaschSampler package for demonstration purposes.

rstats can be used to obtain the 0/1 values for any of the sampled matrices (see second example below). Please note, that the output from the user function is stored in a list where the number of components corresponds to the number of matrices passed to the user function (see third example).

See Also

rsampler, rsextrobj

Examples

ctr <- rsctrl(burn_in = 10, n_eff = 5, step=10, seed = 12345678, tfixed = FALSE)
mat <- matrix(sample(c(0,1), 50, replace = TRUE), nr = 10)
rso <- rsampler(mat, ctr)
rso_st <- rstats(rso,phi.range)
unlist(rso_st)

# extract the third generated matrix
# (here, the first is the input matrix)
# and decode it into rsmat

rso2 <- rsextrobj(rso,4,4)
summary(rso2)
rsmat <- rstats(rso2, function(x) matrix(x, nr = rso2$n))
print(rsmat[[1]])

# extract only the first r rows of the third generated matrix

mat<-function(x, nr = nr, r = 3){
  m <- matrix(x, nr = nr)
  m[1:r,]
}
rsmat2 <- rstats(rso2, mat, nr=rso$n, r = 3)
print(rsmat2[[1]])

# apply a user function to the decoded object
print(phi.range(rsmat[[1]]))

eRm documentation built on May 29, 2024, 2:12 a.m.