Return a matrix of shape `(world_n_dim, pixel_n_dim)`

where each entry
`[i, j]`

is the partial derivative d(world_i)/d(pixel_j) at the requested
pixel position.

- Parameters
**wcs**`WCS`

The WCS transformation to evaluate the derivatives for.

***pixel**floatThe scalar pixel coordinates at which to evaluate the derivatives.

**normalize_by_world**boolIf `True`

, the matrix is normalized so that for each world entry
the derivatives add up to 1.