Regression with some part of the array

Suppose I have x vector=[ 1 5 6 7 8 3 2 ] and corresponding y vector [2 9 4 6 4 5 6].

How to run regression for y on x for x>3.

Thanks.

Answer 1

[Jakob Sørensen]

x = [ 1 5 6 7 8 3 2 ];
y = [ 2 9 4 6 4 5 6 ];

idx = find(x > 3); % Returns the indexes where x is larger than 3

plotregression(x(idx), y(idx)); % Only uses the indexes of the vectors, where x were larger than 3

Replace with other regression methods, depending on what you need.