Couldn't find the position of a value in vector

tryna find a value's location but gives me empty double row vector, why?

My vector is q and its size 1x4406 double. couldn't find out where 0.0500 is. Tried to use this " k=find(q==0.0500) " but didn't get anything worth.

Thanks in advance

Answer 1

[the cyclist]

The value is not exactly equal to 0.05, due to floating point representation. Try

tol = 1.e-6;
k=find(abs(q-0.0500)<tol);

Read this documentation page about floating point for details.

[Enez Furkan Cihan]

Didn't work. still gives empty vector Actually, i'd not able to understand why you substract 0.0500.

Edit: I go through the actual vector q, to find out where 0.0500 is, and there're 3 pieces. meaning more than one. Is that why matlab couldn't give me the location? How can I get the first 0.0500's location then.

[the cyclist]

Can you put the vector q in a MAT file and upload it?

[Enez Furkan Cihan]

here it is. Thanks for your time by the way.

[the cyclist]

Here are the elements that are nearest 0.05. Note that none of them are equal to 0.05. They are also not even with 1.e-6, which is why my code did not work.

You can change my value of tol to get as close as you need.

format long
q(2198:2206)

ans =

  Columns 1 through 6

   0.049918594104308   0.049941269841270   0.049963945578231   0.049986621315193   0.050009297052154   0.050031972789116

  Columns 7 through 9

   0.050054648526077   0.050077324263039   0.050100000000000

[Enez Furkan Cihan]

how i couldn't think that! Thank you so much. I appreciate.