Xcontrast: Xcontrast
In rms: Regression Modeling Strategies

Xcontrast

R Documentation

Xcontrast

Description

Produce Design Matrices for Contrasts

Usage

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

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()].