%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2021-10-06 14:46:34
 % @LastEditTime: 2021-10-07 17:06:35

 % Forming Phi_i for each component 
 % [t1,t2,t3, x, y, len, sin(theta)]
%--------------------------
function [tmpPhi]=tPhi(xy,LSgridx,LSgridy) 
    p = 6;
    st = xy(7); % sin
    ct = sqrt(abs(1-st*st));  % cos

    x1 = ct*(LSgridx - xy(4)) + st*(LSgridy - xy(5)); 
    y1 = -st*(LSgridx - xy(4))+ ct*(LSgridy -xy(5)); 

%     bb = xy(1);
    bb = (xy(2) + xy(1)-2*xy(3)) / 2 / xy(6)^2*x1.^2 + (xy(2)-xy(1))/2*x1/xy(6) + xy(3); 
    tmpPhi = -((x1).^p/xy(6)^p + (y1).^p./bb.^p - 1); 
end