fit_contrasts: Fit Contrasts for Linear Model

In bbuchsbaum/fmrireg: R package for the anlysis of fmri data

Fit Contrasts for Linear Model

Description

This function calculates contrasts for a fitted linear model.

Usage

fit_contrasts(lmfit, conmat, colind, se = TRUE)

Arguments

lmfit	The fitted linear model object.
conmat	The contrast matrix or contrast vector.
colind	The subset column indices in the design associated with the contrast.
se	Whether to compute standard errors, t-statistics, and p-values (default: TRUE).

Value

A list containing the following elements:

• conmat: Contrast matrix.

• sigma: Residual standard error.

• df.residual: Degrees of freedom for residuals.

• estimate: Estimated contrasts.

• se: Standard errors of the contrasts (if se = TRUE).

• stat: t-statistics for the contrasts (if se = TRUE).

• prob: Probabilities associated with the t-statistics (if se = TRUE).

• stat_type: Type of the statistics calculated.

Examples

data(mtcars)
lm_fit <- lm(mpg ~ wt + qsec + am, data = mtcars)
contrast_matrix <- matrix(c(0, -1, 1), nrow = 1, byrow = TRUE)
fit_contrasts(lm_fit, contrast_matrix, c(2, 3))

bbuchsbaum/fmrireg documentation built on May 16, 2023, 10:56 a.m.