Subscript indices must either be real positive integers or logicals. Not getting why this is happening?

x=[.4 1 1.4 1.9 2.4]
y=[.3 .6 .9 1.2 1.5]
for (i=1:10)
    for (j=1:10)
        T(x,y)=x.^2+.6.*x.*y.^3-2.*y.^4
    end
end
surf(T')

Thats what I have and it keeps giving me the error on my formula. I googled this but I should have rational numbers. Lost. Please help!

Answer 1

[Walter Roberson]

You are using x as a subscript in T(x,y)=x.^2+.6.*x.*y.^3-2.*y.^4 . Your first x is 0.4 which is not a positive integer

Assign to T(j,i) instead.

(I immediately see another problem but I will let you find it)

[Chris]

I found the other problem its got to be x(i)^2. Thanks!

Answer 2

[Image Analyst]

x and y are row and column so you can't have the 0.4th row of a matrix. You can't have the 0.3th column. You can make T an image array but you need to give it integer row and column, not fractional x and y values.