Vector representations

In NNGeometry, vectors are not just a bunch of scalars, but they have a semantic meaning.

• nngeometry.object.vector.PVector objects are vectors living in the parameter space of a neural network model. An example of such vector is \(\delta \mathbf w\) in the EWC penalty \(\delta \mathbf w^\top F \delta \mathbf w\).

• nngeometry.object.vector.FVector objects are vectors living in the function space of a neural network model. An example of such vector is \(\mathbf{f}=\left(f\left(x_{1}\right),\ldots,f\left(x_{n}\right)\right)^{\top}\) where \(f\) is a neural network and \(x_1,\ldots,x_n\) are examples from a training dataset.