ORTHOGONALITY AND LEAST SQUARES
 

Orthogonal Vectors
Norm
Unit Vector
Orthonormal Vectors
Orthogonal Complement
Orthogonal Projection
Cauchy-Schwarz Inequality
Angle Between Two Vectors
Gram-Schmidt Process
QR Factorialization
Transpose
Symmetric and Skew-symmetric Matrices
Orthogonal Matrices
Least Squares Solutions
Matrix of an Orthogonal Projection
QR Factorialization
How to Examples Exercise
How to:
QR Factorialization is an extension of the
Gram-Schmidt Process. Here we take a matrix A, whose columns form a regular basis v1, ... , vM and we split it into the product of two other matrices, Q and R.

Q has the property that its columns form an orthonormal basis for A, w1, ... , wM.

R has the following properties:
     R(1, 1) = norm(v1)
     R(J, J) = norm(vJ - projVJminus1vJ) (J > 1)
     R(I, J) = dot(wI, vJ) (I < J)
     R(I, J) = 0 (I > J)


To compute these two matrices using MATLAB simply input:
     [Q, R] = qr(A)
    

Examples:



Exercise: