plot.rasch {ltm} | R Documentation |
Produces the Item Characteristic Curves or Surfaces for fitted rasch
objects.
plot.rasch(x, cx = NULL, cy = NULL, ...)
x |
an object inheriting from class rasch . |
cx |
the x-coordinate to be passed to legend . |
cy |
the y-coordinate to be passed to legend . |
... |
extra graphical parameters to be passed to lines . |
Item characteristic curves (also known as item response functions) show how the probability of a positive response, in each item, increases with the values of the latent variable (ability).
## Item Characteristic Curves for the Wirs data: m <- rasch(Wirs) plot(m) ## Item Characteristic Curves for the Lsat data: m <- rasch(Lsat) plot(m, cx=1.5, cy=0.4)