gprMax/gprMax/subgrids/multi.py

# Copyright (C) 2015-2019: The University of Edinburgh
#                 Authors: Craig Warren and Antonis Giannopoulos
#
# This file is part of gprMax.
#
# gprMax is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# gprMax is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with gprMax.  If not, see <http://www.gnu.org/licenses/>.

from ..receivers import Rx


class ReferenceRx(Rx):
    """Receiver that mimicks a receiver in coarse grid.
        We often want to compare an output in a fine reference solution with a
        the solution in the coarse grid of a subgridded solution. This receiver
        moves the output points in the fine grid such that they are in the same
        position as the coarse grid.
    """

    def get_field(self, str_id, field):
        """Return the field value at the equivalent coarse yee cell.

        Args:
            str_id (str): 'Ex' etc...
            field (nparray): Numpy array of grid.Ez

        Returns:
            e (float): Field value.
        """

        d = {
            'Ex': self.get_Ex_from_field,
            'Ey': self.get_Ey_from_field,
            'Ez': self.get_Ez_from_field,
            'Hx': self.get_Hx_from_field,
            'Hy': self.get_Hy_from_field,
            'Hz': self.get_Hz_from_field
        }

        e = d[str_id](field)

        return e

    def get_Ex_from_field(self, Ex):
        """Return the Ex field value from the equivalent coarse yee cell.

        Args:
            Ex (nparray): Numpy array of Ex field.

        Returns:
            e (float): Ex field value.
        """

        # offset = ratio // 2
        e = Ex[self.xcoord + self.offset, self.ycoord, self.zcoord]
        return e

    def get_Ey_from_field(self, Ey):
        """Return the Ey field value from the equivalent coarse yee cell.

        Args:
            Ey (nparray): Numpy array of Ey field.

        Returns:
            e (float): Ey field value.
        """
        e = Ey[self.xcoord, self.ycoord + self.offset, self.zcoord]
        return e

    def get_Ez_from_field(self, Ez):
        """Return the Ez field value from the equivalent coarse yee cell.

        Args:
            Ez (nparray): Numpy array of Ez field.

        Returns:
            e (float): Ez field value.
        """

        e = Ez[self.xcoord, self.ycoord, self.zcoord + self.offset]
        return e

    def get_Hx_from_field(self, Hx):
        """Return the Hx field value from the equivalent coarse yee cell.

        Args:
            Hx (nparray): Numpy array of Hx field.

        Returns:
            e (float): Hx field value.
        """
        e = Hx[self.xcoord, self.ycoord + self.offset, self.zcoord + self.offset]
        return e

    def get_Hy_from_field(self, Hy):
        """Return the Hy field value from the equivalent coarse yee cell.

        Args:
            Hy (nparray): Numpy array of Hy field.

        Returns:
            e (float): Hy field value.
        """
        e = Hy[self.xcoord + self.offset, self.ycoord, self.zcoord + self.offset]
        return e

    def get_Hz_from_field(self, Hz):
        """Return the Hz field value from the equivalent coarse yee cell.

        Args:
            Hz (nparray): Numpy array of Hz field.

        Returns:
            e (float): Hz field value.
        """
        e = Hz[self.xcoord + self.offset, self.ycoord + self.offset, self.zcoord]
        return e