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function g = sigmoid(z)

%SIGMOID Compute sigmoid function
%J = SIGMOID(z) computes the sigmoid of z.

g = 1.0 ./ (1.0 + exp(-z));

end

I'm going through the Andrew Ng Coursera course. I doubt that how exp(-z) is computed directly while z is a matrix?

Avi
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akib
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  • Word of advice: You are really have to think in terms of vectors and matrices instead of scalars (ok, an scalar is just a funny word to say "single number"). This will be particularly important when calculating the loss too! – Juan Antonio Gomez Moriano Jan 14 '19 at 21:35

1 Answers1

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In many languages and libraries, operations that apply to a scalar can be applied to vectors, matrices and tensors. They're just applied element-wise, and the result is another vector, matrix, etc with each value transformed by that function.

Sean Owen
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