Why its showing error using vertcat?

x = [0 1 2 3 4 5]
y = [2.2 7.7 13.6 27.2 40.9 61.1]

sumx = 0;
sumy = 0;
sumx2 = 0;
sumx3 = 0;
sumx4 = 0;
sumxy = 0;
sumx2y = 0;

n = length(x);

for i=1:n
    sumx = sumx + x(i);
    sumy = sumy + y(i); 
    sumx2 = sumx2 + ((x(i))^2); 
    sumx3 = sumx3 + ((x(i))^3); 
    sumx4 = sumx4 + ((x(i))^4); 
    sumxy = sumxy + (x(i)*y(i));
    sumx2y= sumx2y + (((x(i))^2)*y);
 
end


D= det([n sumx sumx2 ; sumx sumx2 sumx3 ; sumx2 sumx3 sumx4]);
a0=det([sumy sumxy sumx2y ; sumx sumx2 sumx3 ; sumx2 sumx3 sumx4])/D;
a1=det([sumy sumxy sumx2y ; n sumx sumx2 ; sumx2 sumx3 sumx4])/D;
a2=det([sumy sumxy sumx2y ; n sumx sumx2 ; sumx sumx2 sumx3])/D;

ym= a0 +(a1*x) + (a2*x.^2)

Answer 1

[Stephen23]

I suspect that this line

sumx2y= sumx2y + (((x(i))^2)*y);

requires indexing into y, e.g.:

sumx2y = sumx2y + (x(i)^2)*y(i);

[Sabbir Hossain]

Thanks a lot! :D