I have this small code. If statement fails to execute when x(i)<=10^0 say for 10^-5, 10^-1 or 10^0 even though matrix x contains the given elements

clear all
clc
y=10^-8;
z=1;
x(1)=y;
for i=0:16
    for j=1:9
        x(z+1)=x(z)+y;
        z=z+1;
    end
    y=y*10;
end
[~,m]=size(x);
u=1;
for i=1:m
    if x(i)==0.01
        u=u+1
    end
end

[Stephen23]

Learn about floating point numbers:

http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F

Answer 1

[Michael Haderlein]

For the third time today, the answer is floating point arithmetics:

>> [f,ind]=min(abs(x-.01))

f =

     1.7347e-18

ind =

      55

So the 55th element of x is close to 0.01, but it actually isn't 0.01. Comparing double values, you should give some threshold under which two numbers are considered equal. E.q.

if abs(x(i)-.01)<1e-6

@Guillaume has given a good link for further information here: http://de.mathworks.com/matlabcentral/answers/182376-find-function-and-vectors-gives-empty-matrix-1-by-0#comment_270986

[K Chiranjeevi Reddy]

It's working. Learnt a lot about floating point numbers Thanks a lot Micheal Haderlein