proj

proj — projection

Calling sequence

P = proj(X1,X2)

`X1,X2`	: two real matrices with equal number of columns
`P`	: real projection matrix (`P^2=P`)

P is the projection on X2 parallel to X1.



X1=rand(5,2);X2=rand(5,3);
P=proj(X1,X2);
norm(P^2-P,1)
trace(P)    // This is dim(X2)
[Q,M]=fullrf(P);
svd([Q,X2])   // span(Q) = span(X2)

F. D.; ;