Hat Matrix Example
Further Matrix Results for Multiple Linear Regression.
Hat matrix example. The hat matrix H is defined in terms of the data matrix X. Thus H ijis the rate at which the ith tted value changes as. MathbfH mathbfX mathbfXtopmathbfX-1 mathbfXtop.
And determines the fitted or predicted values since. Advantages of a matrix structure. What is the Hat matrix known in econometrics as the projection matrix P in regressionA picture of what the Hat matrix does in regressionHow does the hat m.
The standard hat matrix is written. The matrix H is called the hat matrix because it maps the vector of observed values into a vector of fitted values. In locally weighted scatterplot smoothing LOESS for example the hat matrix is.
In uence Since His not a function of y we can easily verify that mb iy j H ij. H X XTX 1XT and determines the fitted or predicted values since. H X XTX 1XT.
An example of a quadratic form is given by Note that this can be expressed in matrix notation as where A is a symmetric matrix do on board. Where H XXT X 1XT is an n nmatrix which puts the hat on y and is therefore. H X X T X 1 X T.
Fewer people more work. Easy to learn how to draw a Matrix Diagram. A matrix structure has its pros and cons.