Normalization Formulas

[Pavel_Grobov]

Hi,
I need to clarify about normalizing formula.

Dr Andrew wrote that sigma^2 = 1/m * sum(x(i) ^ 2) and then X = X/sigma ^ 2.
But in clarification it is X = X/sigma.

So what is the right formula ?

Another thing is about sigma^2 formula it is 1/m * sum(x(i)^2) ot it is
1/m * sum(x(i) - mean)^2 ?

[rmwkwok]

@Pavel_Grobov

So what is the right formula ?

Hello @Pavel_Grobov, the clarification page has the correct formula: X = X/sigma.

@Pavel_Grobov

Another thing is about sigma^2 formula it is 1/m * sum(x(i)^2) ot it is
1/m * sum(x(i) - mean)^2 ?

step 3 is based on the outcome of the step 2, and step 2 already centered the X, so we don’t need to do it again in step 3.

Cheers,
Raymond

[Pavel_Grobov]

Thank you very much @rmwkwok !

[rmwkwok]

You are welcome @Pavel_Grobov!