remove Nan from a row vector using if statement only

I have a row vector. Ch (1,1155). I want to remove columns that have NaN.

for k=1:122

p=1;

for m=1:1155

if( (ch(1,m) ~= NaN )

Datan(1,p)=ch(1,m);

p=p+1

end

end

end

But the above codes doesn't remove NAN

[Rik]

As a side note: your outer loop does not affect the rest of your code, so it is useless.

Answer 1

[madhan ravi]

isnan() would suffice your need

doc isnan

[Guillaume]

It's more than suffice, it's necessary!

[madhan ravi]

True , should have used "should" instead of "would" , thank you for the pointer :)

Answer 2

[Guillaume]

But the above codes doesn't remove NAN

One important property of NaN is that NaN is never equal to anything, including NaN. Hence NaN == NaN is always false, and NaN ~= NaN is always true.So, yes your code can't work.

As others have said, you have to use isNaN to check if a number is NaN. As usual in matlab, isNaN works on matrices too, so there's no point in using a loop:

datan = ch(~isnan(ch)); %as long as ch is a vector

It's unclear what the purpose of the k loop is in a code.

Finally, if you are hell-bent on using a loop, you should never hard code the end of a loop when you're looping over the elements of a matrix/vector. Always ask matlab how many elements there are. That way if the number of elements in the matrix/vector changes, you don't have to edit your code:

for m = 1:numel(ch)  %iterate over the elements of ch

Answer 3

[Stephan]

Datan=ch(~isnan(ch));