# SimPEG.maps.Weighting.deriv#

Weighting.deriv(m, v=None)[source]#

Derivative of mapping with respect to the input parameters.

For a weighting mapping $$\mathbf{u}(\mathbf{m})$$ that scales the input parameters in the model $$\mathbf{m}$$ by their corresponding weights $$\mathbf{w}$$; i.e.:

$\mathbf{u}(\mathbf{m}) = \mathbf{w} \dot \mathbf{m},$

the derivative of the mapping with respect to the model is a diagonal matrix of the form:

$\frac{\partial \mathbf{u}}{\partial \mathbf{m}} = diag (\mathbf{w})$
Parameters
m

A vector representing a set of model parameters

v

If not None, the method returns the derivative times the vector v

Returns
scipy.sparse.csr_matrix

Derivative of the mapping with respect to the model parameters. If the input argument v is not None, the method returns the derivative times the vector v.