a(a==NaN) does not find NaN's in matrix. What to do?

I have

 a=1 NaN 2 6

I want to change the NaN to 0 but

 a(a==NaN)=0

does not work and gives me

 a =
          1.00           NaN          2.00          6.00

What did i do wrong?

Answer 1

[Sean de Wolski]

NaNs are not equal to themselves!

You could thus do either of these:

*  a(isnan(a))=0; %isnan
*  a(a~=a) = 0; %nans aren't equal to themselves

[Sharon]

Thanks..

Answer 2

[Thomas]

Sharon, you are unable to replace the NaN because

NaN ~= NaN (in matlab NaN's are unequal) you can check this by

isequal(NaN,NaN)
ans =
     0

to replace NaN's use the isnan function

 doc isnan

For your example you need

 a(isnan(a))=0
 a =
          1.00             0          2.00          6.00

[Sharon]

Thanks..