Deleted redundant FD_order1 because already contained in FD_simple.

src/FiniteDifference/FD_order1.hpp

-//
-// Created by jstark on 17.05.21.
-//
-
-#ifndef OPENFPM_NUMERICS_SRC_FINITEDIFFERENCE_FD_ORDER1_HPP
-#define OPENFPM_NUMERICS_SRC_FINITEDIFFERENCE_FD_ORDER1_HPP
-
-// Include OpenFPM header files
-#include "Grid/grid_dist_id.hpp"
-
-/**@brief Computes the forward finite difference of a scalar property on the current grid node.
- *
- * @tparam Field Size_t index of property for which the gradient should be computed.
- * @tparam gridtype Type of input grid.
- * @tparam keytype Type of key variable.
- * @param grid Grid, on which the gradient should be computed.
- * @param key Key that contains the index of the current grid node.
- * @param d Variable (size_t) that contains the dimension.
- * @return Forward finite difference for the property under index Field on the current node with index key.
- */
-template <size_t Field, typename gridtype, typename keytype>
-double FD_forward(gridtype & grid, keytype & key, size_t d)
-{
-	return (grid.template get<Field> (key.move(d, 1)) - grid.template get<Field> (key)) / grid.getSpacing()[d];
-}
-/**@brief Computes the backward finite difference of a scalar property on the current grid node.
- *
- * @tparam Field Size_t index of property for which the gradient should be computed.
- * @tparam gridtype Type of input grid.
- * @tparam keytype Type of key variable.
- * @param grid Grid, on which the gradient should be computed.
- * @param key Key that contains the index of the current grid node.
- * @param d Variable (size_t) that contains the dimension.
- * @return Backward finite difference for the property under index Field on the current node with index key.
- */
-template <size_t Field, typename gridtype, typename keytype>
-double FD_backward(gridtype & grid, keytype & key, size_t d)
-{
-	return (grid.template get<Field> (key) - grid.template get<Field> (key.move(d, -1))) / grid.getSpacing()[d];
-}
-
-
-
-
-
-
-
-#endif //OPENFPM_NUMERICS_SRC_FINITEDIFFERENCE_FD_ORDER1_HPP
-