linop.Gradient

bartorch.linop.Gradient()

Forward finite differences along axes, BART’s linop_grad.

The boundary is circular: at the last index along an axis the difference is the first entry minus the last. Constants are the null space.

Parameters:

• shape (tuple of int) – Domain, C order.

• axes (int or tuple of int) – Axes to difference along, each at most once.

Returns:

Codomain (len(axes), *shape). The components are in ascending axis order, whatever the order of axes.

Return type:

LinearOperator

Raises:

ValueError – When an axis is named twice, or the new axis would exceed BART’s dimension count.