How to find which postions in a vector has negative values and output them?

i have a vector and need to find the postions which has negative values

Answer 1

[Birdman]

Say your vector is A:

idx=find(A<0)
ANeg=A(idx)

[sairohith mudduluru]

thankyou

Answer 2

[Stephen23]

find is not required, logical indexing is simpler and more efficient:

B = A(A<0)

[Birdman]

need to find the postions 

The user wants it.

[Stephen23]

And logical indexing indexing gives it.