optical (version 1.7.1)

convergenceplot: Convergence plot

Description

Convergence plots displaying efficiency of design, violations of equivalence theorem, and alpha(Step length used) vs. iteration number. These plot are suitable for monitoring the convergence of optimal item calibration algorithm.

Usage

convergenceplot(yyy, refline = c(0.002, 1e-05))

Value

A convergence plot is displayed.

Arguments

yyy

a optical object; the output of a call optical()

refline

reference line

Details

Convergence plots have three panel.

• First panel monitors efficiency of design vs. iteration number

• Second panel monitors violations of equivalence theorem vs. iteration number

• Third panel monitors step size used vs. iteration number

See Also

drawdesign

Examples

# 2PL-models for two items; parameters (a, b)=(1.6, -1) and (1.6, 1), respectively
ip <- cbind(c(1.6, 1.6),c(-1, 1))

yyy <- optical(ip)

convergenceplot(yyy, refline=c(0.002, 0.001*0.005/0.45))