why when i use find command to find the index i face problem

please it is urgent for me, why when i try to find the index of 0.3 it gives me the double information rather than showing the index 3 like others.

Answer 1

[Daniel Pollard]

I had a play with my version of Matlab and found the same result. I think what you've stumbled on is a floating point error. There is a workaround:

t = 0:0.1:1.8;
find(round(t, 10) == 0.3)

ans = 4

This rounds all the elements of t to 10 significant figures before performing find.

Answer 2

[Mathieu NOE]

hello

no , matlab tells you that it could NOT find an exact match to value = 0.3 (there must be a very tiny numerical difference , so use method with a tolerance (to be defined) :

ind  = find(abs(t - 0.3)<tol)