h_vectorization: Vectorization helper for Covariance Plot

In tern.mmrm: Tables and Graphs for Mixed Models for Repeated Measures (MMRM)

Vectorization helper for Covariance Plot

Description

This function vectorizes the upper-diagonal elements of a symmetric matrix (e.g. the covariance matrix) and obtains the lag and time distance between pairs of observations if the time values are part of the names or are part of the matrix column and row names.

Usage

h_vectorization(vcov_matrix, time_prefix = NULL)

Arguments

vcov_matrix	(matrix) symmetric covariance matrix with identical row and column names.
time_prefix	(string) string in the names of vcov_matrix that precedes the time point value.

Value

A data.frame with the upper-diagonal elements of vcov_matrix. In the context of repeated measures, this matrix contains the association between pairs of measurements taken at different time points. It contains the following columns:

• Vect: the upper-diagonal elements of vcov_matrix.

• time_diff: the difference between column and row times.

• lag: the lag, defined as the difference between column and row ranks.

• rank_row: the row rank.

• rank_col: the column rank.

tern.mmrm documentation built on Sept. 30, 2024, 9:20 a.m.