eqp.eq: The equipercentile method of equating
In jagonzalb/SNSequate: Standard and Nonstandard Statistical Models and Methods for Test Equating

Description Usage Arguments Details Value Author(s) References See Also Examples

This function implements the equipercentile method of test equating as described in Kolen and Brennan (2004).

1	eqp.eq(sx, sy, X, Ky = max(sy))

`sx`	A vector containing the observed scores on test X
`sy`	A vector containing the observed scores on test Y
`X`	Either an integer or vector containing the values on the scale to be equated.
`Ky`	The total number of items in test form Y to which form X scores will be equated

The function implements the equipercentile method of equating as described in Kolen and Brennan (2004). Given observed scores sx and sy, the functions calculates

G^{-1}(F(x))

where F and G are the cdf of scores on test forms X and Y, respectively.

A two column matrix with the values of phi() (second column) for each scale value x (first column)

Jorge Gonzalez B. <jgonzale@mat.puc.cl>

Gonzalez, J. (2014). SNSequate: Standard and Nonstandard Statistical Models and Methods for Test Equating. Journal of Statistical Software, 59(7), 1-30.

Kolen, M., and Brennan, R. (2004). Test Equating, Scaling and Linking. New York, NY: Springer-Verlag.

mea.eq, lin.eq, ker.eq

### Example from Kolen and Brennan (2004), pages 41-42:
### (scores distributions have been transformed to vectors of scores)

sx<-c(0,0,1,1,1,2,2,3,3,4)
sy<-c(0,1,1,2,2,3,3,3,4,4)
x<-2
eqp.eq(sx,sy,2)

# Whole scale range (Table 2.3 in KB)
eqp.eq(sx,sy,0:4)