projection matrix

noun2

1. •
   A transformation matrix whose associated transformation is a projection.

   • The resultant eigenvalues of the angular momentum are independent of direction, but the projection matrices are dependent. — 2006
2. •
   A matrix that maps a vector of response (dependent variable) values to a vector of fitted or predicted values.

   • Caswell (1989) pointed out that most linear stage-structured models have both primitive and irreducible projection matrices.[…]The projection matrix M shown in the table is then calculated as PS + R. — 1999