cov.surr.gs {SurrogateSeq} | R Documentation |
Computes variances and standardized covariance matrix for the group sequential statistic
Description
Computes variances and standardized covariance matrix for the group sequential statistic
Usage
cov.surr.gs(s0.4.est, s1.4.est, sa.0, ya.0, nb.0, nb.1, full.matrix = TRUE,
naive = FALSE)
Arguments
s0.4.est |
surrogate marker in the control group which is used for estimating means and covariances of S0, S1 in the Study B data. For designing tests (e.g., finding boundaries) these may come from Study A data, but for analyzing tests these may come from Study B data. Number of columns is the number of stages, number of rows may differ from rows in sa.0 |
s1.4.est |
surrogate marker in the treated group which is used for estimating means and covariances of S0, S1 in the Study B data. For designing tests (e.g., finding boundaries) these may come from Study A data, but for analyzing tests these may come from Study B data. Number of columns is the number of stages, number of rows may differ from rows in sa.0 |
sa.0 |
surrogate marker in the control group in Study A |
ya.0 |
primary outcome in the control group in Study A |
nb.0 |
sample size for the control group in Study B |
nb.1 |
sample size for the treated group in Study B |
full.matrix |
if TRUE, the standardized covariance matrix is provided; default is TRUE |
naive |
user should set to TRUE to compute covariance for "cumulative" test statistic, FALSE for naive statistic that only uses study B data from timepoint J at the J-th analysis; default is FALSE |
Value
Returns a list:
var.vec.del |
variance vector computed by the delta method |
cov.stand.del |
if full.matrix = TRUE, covariance matrix of the standardized test statistic computed by the delta method |
var.vec.samp |
variance vector computed by the sample mean and covariance of s0.4.est and s1.4.est |
cov.stand.samp |
if full.matrix = TRUE, covariance matrix of the standardized test statistic computed by the sample mean and covariance of s0.4.est and s1.4.est |
Author(s)
Jay Bartroff