W3_E6: dZ1 equation: Is '*' a Multiplication Or Convolution?

[Anurag_Dixit]

Subject: W3_E6: dZ1 equation: Is ‘*’ a Multiplication Or Convolution?

Hello Everyone,
dZ1 calculation is defined (attached) in the problem.

Query: Is ‘*’ a Multiplication Or Convolution?

Sincerely,
A

[Kic]

Hi @Anurag_Dixit

The * is a multiplication operator.

[TMosh]

To elaborate a tiny bit, it’s an element-wise product. The two operands must be the same size, or must be broadcast-able .

[Anurag_Dixit]

Thanks Kic, TMosh for the response.

Equation: dZ1 = W[2]TdZ[2] * g[1]’(Z[1])
where g[1]’(Z[1]) = (1- square(A1))

Query:
W[2]TdZ[2]: Is this also a multiplication OR, should np.dot be used.

Sincerely,
A

[Kic]

Hi @Anurag_Dixit ,

Here is a link to a thread discussing the difference of * the elementwise multiplication and the and dot product operation, and how to spot them in a formula.