SGP (version 2.2-0.0)

createKnotsBoundaries: Function to create Knots and Boundaries from supplied data in LONG format.

Description

The function createKnotsBoundaries creates Knots, Boundaries and Loss/Hoss scores for subsequent use and embedding in SGPstateData. Function can be called separately but is usually called as part of prepareSGP. See examples below.

Usage

createKnotsBoundaries(tmp.data,
	 knot.cut.percentiles=c(0.2,0.4,0.6,0.8))

Value

Returns a list containing Knots, Boundaries and Loss/Hoss scores.

Arguments

tmp.data

Data supplied to function in LONG format. See sgpData_LONG for an exemplar. tmp.data must contain, at least, variables 'VALID_CASE', 'CONTENT_AREA', 'SCALE_SCORE', 'GRADE'.

knot.cut.percentiles

A numeric vector of quantiles of 'SCALE_SCORE' to be used as the cut points. Default is to use the 20th, 40th, 60th, and 80th percentiles (i.e., c(0.2,0.4,0.6,0.8)).

Author

Damian W. Betebenner

Examples

if (FALSE) {
### Run on supplied long data

DEMO_Knots_Boundaries <- createKnotsBoundaries(sgpData_LONG)

### Run as part of prepareSGP

### First NULL out knots and boundaries embedded in SGPstateData

SGPstateData[["DEMO"]][["Achievement"]][["Knots_Boundaries"]] <- NULL
Demonstration_SGP <- prepareSGP(sgpData_LONG)
}