Clarification on dimensions in first exercise notebook

Clarification on dimensions in first exercise notebook

de Lasse Kreimendahl -
Número de respuestas: 1

Hi Gregor,

I'm afraid in the first exercise notebook there is a slight mix-up with the dimensions of the matrices and vectors involved. In the introductory text of 1.2.2 it says W \in \mathbb{R}^{m \times n} and b \in \mathbb{R}^{n}. However, if the input vector is x \in \mathbb{R}^{n} and the output vector is y \in \mathbb{R}^{m}, as specified in the code blocks, and following y = xW + b, then the weight matrix has the dimension W \in \mathbb{R}^{n \times m} and the bias vector is b \in \mathbb{R}^{m}. The same applies to the text in 1.2.4, where n and m have been swapped. 

Please let me know if I am wrong. 

Best regards,

Lasse

En respuesta a Lasse Kreimendahl

Re: Clarification on dimensions in first exercise notebook

de Gregor Geigle -
Hi,

indeed, while the use of n and m is internally correct dimension-wise for the text and the code, respectively, the notation between the text and code is inconsistent. I will update the notebook.