double presition problem

Hello to everyone, I want find function to return coordinates of a matrix,but it returns Empty matrix: 0-by-1 a lot of times.I think that is a double presicion problem.I remember taht there was a matlab faq that analysed this problem,but i can't find it.Could anybody help me with this?Thank's in advantage!

Answer 1

[the cyclist]

I think you mean problems arising from the use of "floating point" representation of numbers, so you might want to search on "floating point" and "matlab" to find some info. Here is one resource from the Mathworks site:

http://www.mathworks.com/support/tech-notes/1100/1108.html

It points to other sources of information that also might help you.

If that does not answer your question, you could post some of your code maybe find some help sorting things out.

Answer 2

[bym]

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

instead of

find(x==1)

use

find(abs(x-1)<=tol)

Answer 3

[Mary Kodogianni]

The subject is that i want to find the coordinates of a matrix that have the same values with some items and find function was an easy way to do this.