kwant.continuum.lambdify¶

kwant.continuum.lambdify(expr, locals=None)[source]¶

Return a callable object for computing a continuum Hamiltonian.

Warning

This function uses eval (because it calls sympy.sympify), and thus should not be used on unsanitized input.

If necessary, the given expression is sympified using kwant.continuum.sympify. It is then converted into a callable object.

Parameters

expr (str or SymPy expression) – Expression to be converted into a callable object
locals (dict or None (default)) – Additional definitions for sympify.

Examples

>>> f = lambdify('a + b', locals={'b': 'b + c'})
>>> f(1, 3, 5)
9

>>> ns = {'sigma_plus': [[0, 2], [0, 0]]}
>>> f = lambdify('k_x**2 * sigma_plus', ns)
>>> f(0.25)
array([[ 0.   ,  0.125],
       [ 0.   ,  0.   ]])