MATLAB: I am getting the following error for the below code: Subscript indices must either be real positive integers or logicals. How can i remove that error.

while loop

clc
clear all
g=9.81;
u=10;
t=0:.1:10;
y(1)=0;
while (y(t)>=0)
y(t)=(u*t)-(0.5*g*t.*t)
end

Best Answer

You have
t=0:.1:10;
so t is a vector containing 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0
You have
while (y(t)>=0)
but t is the vector discussed above, so your line is equivalent to asking
while y([0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0]) >= 0
However, this attempts to subscript y with 0 and non-integers.
I suggest you have a look at https://www.mathworks.com/matlabcentral/answers/353353-how-can-i-use-interval-with-decimal-at-the-end-of-a-count-in-for-loop-e-g-t-1-1-18-7#comment_478299
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