Exemple #1
0
    def generate_subs(deriv_order, function, index):
        dim = retrieve_dimensions(index)[0]

        if dim.is_Time:
            fd_order = function.time_order
        elif dim.is_Space:
            fd_order = function.space_order
        else:
            # Shouldn't arrive here
            raise TypeError("Dimension type not recognised")

        subs = {}

        mapper = {dim: index}

        indices, x0 = generate_indices(function, dim,
                                       fd_order, side=None, x0=mapper)

        coeffs = sympy.finite_diff_weights(deriv_order, indices, x0)[-1][-1]

        for j in range(len(coeffs)):
            subs.update({function._coeff_symbol
                        (indices[j], deriv_order, function, index): coeffs[j]})

        return subs
Exemple #2
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    def generate_subs(deriv_order, function, dim):

        if dim.is_Time:
            fd_order = function.time_order
        elif dim.is_Space:
            fd_order = function.space_order
        else:
            # Shouldn't arrive here
            raise TypeError("Dimension type not recognised")

        side = form_side((dim, ), function)
        stagger = side.get(dim)

        subs = {}

        indices, x0 = generate_indices(function,
                                       dim,
                                       dim.spacing,
                                       fd_order,
                                       side=None,
                                       stagger=stagger)

        coeffs = sympy.finite_diff_weights(deriv_order, indices, x0)[-1][-1]

        for j in range(len(coeffs)):
            subs.update({
                function._coeff_symbol(indices[j], deriv_order, function, dim):
                coeffs[j]
            })

        return subs
Exemple #3
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        def generate_subs(i):

            deriv_order = i.deriv_order
            function = i.function
            dim = i.dimension
            weights = i.weights

            if isinstance(weights, np.ndarray):
                fd_order = len(weights)-1
            else:
                fd_order = weights.shape[-1]-1

            subs = {}

            indices, x0 = generate_indices(function, dim, fd_order, side=None)

            # NOTE: This implementation currently assumes that indices are ordered
            # according to their position in the FD stencil. This may not be the
            # case in all schemes and should be changed such that the weights are
            # passed as a dictionary of the form {pos: w} (or something similar).
            if isinstance(weights, np.ndarray):
                for j in range(len(weights)):
                    subs.update({function._coeff_symbol
                                 (indices[j], deriv_order, function, dim): weights[j]})
            else:
                shape = weights.shape
                x = weights.dimensions
                for j in range(shape[-1]):
                    idx = list(x)
                    idx[-1] = j
                    subs.update({function._coeff_symbol
                                 (indices[j], deriv_order, function, dim):
                                     weights[as_tuple(idx)]})

            return subs
Exemple #4
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        def generate_subs(i):

            deriv_order = i.deriv_order
            function = i.function
            dim = i.dimension
            weights = i.weights

            fd_order = len(weights) - 1

            side = form_side((dim, ), function)
            stagger = side.get(dim)

            subs = {}

            indices, x0 = generate_indices(function,
                                           dim,
                                           dim.spacing,
                                           fd_order,
                                           side=None,
                                           stagger=stagger)

            for j in range(len(weights)):
                subs.update({
                    function._coeff_symbol(indices[j], deriv_order, function, dim):
                    weights[j]
                })

            return subs