TITLE: Symbol for elementwise multiplication of vectors
QUESTION [59 upvotes]: This is a notation question. Assume one is given two vector $\mathbf{a}$  and $\mathbf{b}$, and one constructs a third vector $\mathbf{c}$ whose elements are given by 
$$c_k=a_k b_k$$ 
Is there any standard notation for this simple operation? 
Is the notation below acceptable?
$$\mathbf{c}=\mathbf{a}\otimes \mathbf{b}$$

REPLY [19 votes]: Wikipedia uses $\circ$ (\circ) to denote the Hadamard product (which is the operation you describe)
This answer makes a
good case for $\odot$ (\odot) being used instead.