contrast: Contrast for Model Parameters

In sanon: Stratified Analysis with Nonparametric Covariable Adjustment

Description

Inference by contrast of parameters in a fitted model.

Usage

contrast(
  object,
  C = diag(length(object$b)),
  confint = FALSE,
  level = 0.95,
  ...
)

## S3 method for class 'contrast'
print(x, ...)

Arguments

object, x	an object of class "sanon", usually, a result of a call to sanon.
C	contrast matrix. The number of column should be same as the length of b in outputs of sanon.
confint	logical value for whether the confidence interval is computed (only if C has one row).
level	the confidence level required (only if C has one row).
...	further arguments passed to or from other methods.

Details

This function provide the inference based on contrast after applying the function sanon. The contrast matrix C should be defined by the user. If the the number of row of C = 1, the confidence interval for the estimator is produced.

Value

C	contrast matrix
Cb	contrast estimates
VCb	variance and covariance matrix of Cb
se	standard error of Cb
level	confidence level
UL	upper confidence limit (only if the number of row of C = 1, otherwise NULL)
LL	lower confidence limit (only if the number of row of C = 1, otherwise NULL)
Q	test statistic
df	degree of freedom
p	p-value

Examples

##### Example 3.2 Randomized Clinical Trial of Respiratory Disorder #####
data(resp)
P = rbind(rep(0, 4), diag(4), rep(0, 4))
out23 = sanon(cbind(baseline, visit1, visit2, visit3, visit4) ~ grp(treatment, ref="P")
 + strt(center) + strt(sex) + covar(age), data=resp, P=P)

# Homogeneity of the xi_k across the four visits
contrast(out23, C=cbind(diag(3), rep(-1, 3)))

# Comparison between treatments for the average of the xi_k across the 4 visits
contrast(out23, C=matrix(rep(1, 4)/4, ncol=4))

sanon documentation built on July 8, 2020, 6:54 p.m.