Hat operator

The hat operator is a mathematical notation with various uses in different branches of science and mathematics. The hat operator is a mathematical notation with various uses in different branches of science and mathematics. In statistics, the hat matrix H projects the observed values y of response variable to the predicted values ŷ: In screw theory, one use of the hat operator is to represent the cross product operation. Since the cross product is a linear transformation, it can be represented as a matrix. The hat operator takes a vector and transforms it into its equivalent matrix.