linear2btl {eba} | R Documentation |
Transforms linear model coefficients to BTL parameter estimates.
linear2btl(object, order=FALSE)
object |
an object of class glm or lm specifying a BTL
model |
order |
logical, does the model include an order effect? Defaults to FALSE |
The design matrix used by lm
or glm
usually results from
a call to pcX
. It is assumed that the reference category is
the first level.
The covariance matrix is estimated by employing the delta method.
See Imrey, Johnson & Koch (1976) for more details.
btl.parameters |
a matrix; the first column holds the BTL parameter estimates, the second column the approximate standard errors |
cova |
the approximate covariance matrix of the BTL parameter estimates |
linear.coefs |
a vector of the original linear coefficients as returned
by glm or lm |
Imrey, P.B., Johnson, W.D., & Koch, G.G. (1976). An incomplete contingency table approach to paired-comparison experiments. Journal of the American Statistical Association, 71, 614–623.
data(celebrities) y1 <- t(celebrities)[lower.tri(celebrities)] y0 <- celebrities[lower.tri(celebrities)] ## Fit BTL model using glm btl.glm <- glm(cbind(y1, y0) ~ pcX(9)[,-1] - 1, binomial) linear2btl(btl.glm)