Module vector

A module for the common differential operators of vector calculus

class findiff.vector.Curl(**kwargs)

The curl operator.

\[{\rm \bf rot} = \nabla \times\]

Is only defined for 3D.

Parameters:

kwargs

exactly one of h and coords must be specified

h

list with the grid spacings of a 3-dimensional uniform grid

coords

list of 1D arrays with the coordinate values along the 3 axes. This is used for non-uniform grids.

acc

accuracy order, must be positive integer, default is 2

Constructor for the VectorOperator base class.

kwargs:

h list with the grid spacings of an N-dimensional uniform grid

coords list of 1D arrays with the coordinate values along the N axes.

This is used for non-uniform grids.

Either specify “h” or “coords”, not both.

class findiff.vector.Divergence(**kwargs)

The N-dimensional divergence.

\[{\rm \bf div} = \nabla \cdot\]
Parameters:

kwargs

exactly one of h and coords must be specified

h

list with the grid spacings of an N-dimensional uniform grid

coords

list of 1D arrays with the coordinate values along the N axes. This is used for non-uniform grids.

acc

accuracy order, must be positive integer, default is 2

Constructor for the VectorOperator base class.

kwargs:

h list with the grid spacings of an N-dimensional uniform grid

coords list of 1D arrays with the coordinate values along the N axes.

This is used for non-uniform grids.

Either specify “h” or “coords”, not both.

class findiff.vector.Gradient(**kwargs)

The N-dimensional gradient.

\[\nabla = \left(\frac{\partial}{\partial x_0}, \frac{\partial}{\partial x_1}, ... , \frac{\partial}{\partial x_{N-1}}\right)\]
Parameters:

kwargs

exactly one of h and coords must be specified

h

list with the grid spacings of an N-dimensional uniform grid

coords

list of 1D arrays with the coordinate values along the N axes. This is used for non-uniform grids.

acc

accuracy order, must be positive integer, default is 2

Constructor for the VectorOperator base class.

kwargs:

h list with the grid spacings of an N-dimensional uniform grid

coords list of 1D arrays with the coordinate values along the N axes.

This is used for non-uniform grids.

Either specify “h” or “coords”, not both.

class findiff.vector.Laplacian(h=[1.0], acc=2)

The N-dimensional Laplace operator.

\[{\rm \bf \nabla^2} = \sum_{k=0}^{N-1} \frac{\partial^2}{\partial x_k^2}\]
Parameters:

kwargs

exactly one of h and coords must be specified

h

list with the grid spacings of an N-dimensional uniform grid

coords

list of 1D arrays with the coordinate values along the N axes. This is used for non-uniform grids.

acc

accuracy order, must be positive integer, default is 2

class findiff.vector.VectorOperator(**kwargs)

Base class for all vector differential operators. Shall not be instantiated directly, but through the child classes.

Constructor for the VectorOperator base class.

kwargs:

h list with the grid spacings of an N-dimensional uniform grid

coords list of 1D arrays with the coordinate values along the N axes.

This is used for non-uniform grids.

Either specify “h” or “coords”, not both.

findiff.vector.wrap_in_ndarray(value)

Wraps the argument in a numpy.ndarray.

If value is a scalar, it is converted in a list first. If value is array-like, the shape is conserved.