givens

givens — Givens transformation

Calling sequence

U=givens(xy)  
U=givens(x,y)  
[U,c]=givens(xy)  
[U,c]=givens(x,y)

`x,y`	: two real or complex numbers
`xy`	: real or complex size 2 column vector
`U`	: 2x2 unitary matrix
`c`	: real or complex size 2 column vector

U = givens(x, y) or U = givens(xy) with xy = [x;y] returns a 2x2 unitary matrix U such that:

U*xy=[r;0]=c.

Note that givens(x,y) and givens([x;y]) are equivalent.



A=[3,4;5,6];
U=givens(A(:,1));
U*A