In mathematics and multivariate statistics, the centering matrix is a symmetric and Idempotent matrix, which when multiplied with a vector has the same effect as subtracting the mean of the components of the vector from every component of that vector.
\(C_n = I_n - \tfrac{1}n J_n\)
Bibliography
“Centering Matrix.” 2021. Wikipedia, June. https://en.wikipedia.org/w/index.php?title=Centering_matrix&oldid=1027624781.