% MT 03 2018/19
% Problem Set 2, Exercise 1

function [ Z ] = hemisphere( X,Y,R )
% hemisphere.m calculates surface points of a sphere
%   both for scalars, vectors and matrices



% A solution for the sphere exists only 
% within a circle around the origin of radius R
% Logical condition in a array implementation

L = (X.^2 + Y.^2 < R.^2);

% Initialize Z (not necessary)
% Z = zeros(SX);

Z = L.*sqrt(R.^2 - X.^2 -Y.^2);

end