Suppose I have a vector $v$ in the complex space $\mathbb{C}^N$ with only a single non-zero element. Is there a standard notation to replace the vector with a scalar equal to the non-zero value of the vector?
Update:
After some thought, I think $v\cdot e_i$ would suffice for this purpose, assuming the index i containing the non-zero element is known. But what if the index is unknown?
You can use the dot product with the vector $(1, \dots, 1)^T$.