plot.trf {irtoys} | R Documentation |
Useful for plotting test response functions. The x
argument of
trf
should better be left out unless something special is required.
## S3 method for class 'trf': plot(x, add = FALSE, main = "Test response function", co = 1, ...)
x |
An object produced by function trf |
add |
When add=T , the IRF is added to a plot, otherwise a new plot is started. Default is F. |
main |
The main title of the plot, given that add=F . |
co |
The colour of the TRF curve. Default is 1 for black. Use co=NA to plot each TRF in a different colour. |
... |
Any additional plotting parameters |
Ivailo Partchev
data(Scored) p.2pl <- est(Scored, model="2PL", engine="ltm") plot(trf(p.2pl))