additiveMatrix: Generate an additive approximation of a data matrix
Description
Constructs a matrix with an additive structure based on the row means,
column means, and the grand mean of the original matrix.
Usage
additiveMatrix(mat)
Value
A numeric matrix of the same dimension as mat, approximating it
using an additive model.
Arguments
mat
A numeric matrix or data frame with numeric entries.
Details
The result is an approximation \(A\) of the original matrix, where:
$$A[i,j] = rowMean[i] + colMean[j] - grandMean$$
This model captures main additive effects of rows and columns, commonly
used in exploratory data analysis or baseline modeling.