Please help! How to express p as the projection of b onto the Col A according to the theory. I know that the component of b orthogonal to ColA is z=b-p(accodfing to the theory )

function [p,z]=proj(A,b)
format
A=shrink(A);
m=size(A,1);
p=[];
z=[];
boolean = true
if ~isequal(size(A,1),size(b,1))
disp("No solution: dimensions of A and b disagree")
display(p)
display(z)
return;
end
y=[A,b];
if ~isequal(rank(y),size(y,2))
disp('b is in Col A')
p=???
z=b-p
return;
end

[Walter Roberson]

What is shrink in this context?

What is the purpose of your variable named boolean ?

[Tianlan Yang]

[Tianlan Yang]

[Walter Roberson]

Please remember that the volunteers do not have a version of MATLAB that can execute pictures of code.

[Tianlan Yang]

Hi, I just want to know how to express the orthogonal projection of one vector to ColA. Thank you.