How can I fix the error:Subscript indices must either be real positive integers or logicals of the code given below

if i<=a && x<b
      Data_tx(i)=1+[(a-i)*x+(a+i+1)*(a-i)*r/2]/(i*r+x);
  elseif i<=a-1 && x<=r
      Data_tx(i)=1+[(a-i-1)*x+(a-i-1)*(a+i)*r/2]/(i*r+x);
  end

[Azzi Abdelmalek]

Give an example that allows to test your code

Answer 1

[Azzi Abdelmalek]

Check your indices, In Matlab the indices should be positive integers, or logical