module Utils
##
 # Copyright (C) 2015 Dynare Team
 #
 # This file is part of Dynare.
 #
 # Dynare 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.
 #
 # Dynare 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 Dynare.  If not, see <http://www.gnu.org/licenses/>.
##

export get_power_deriv

function get_power_deriv(x::Float64, p::Real, k::Int)
    if abs(x)<1e-12 && p>0 && k>p && typeof(p)==Int
        dxp = .0
    else
        dxp = x^(p-k)
        for i = 0:k-1
            dxp *= p
            p -= 1
        end
    end
    return dxp
end

end