Xcontrast( fit, a, b =NULL, a2 =NULL, b2 =NULL, ycut =NULL, weights ="equal", expand =TRUE, Zmatrix =TRUE)
Arguments
fit: an rms or rmsb fit object, not necessarily complete
a: see [rms::contrast.rms()]
b: see [rms::contrast.rms()]
a2: see [rms::contrast.rms()]
b2: see [rms::contrast.rms()]
ycut: see [rms::contrast.rms()]
weights: see [rms::contrast.rms()]
expand: see [rms::contrast.rms()]
Zmatrix: set to FALSE for a partial PO model in which you do not want to include the Z matrix in the returned contrast matrix
Returns
numeric matrix
Details
This is a simpler version of contrast.rms that creates design matrices or differences of them and does not require the fit object to be complete (i.e., to have coefficients). This is used for the pcontrast option in [rmsb::blrm()].