function g = lfmGradientH32(preFactor, gradThetaGamma, compUpsilon1, ...
    compUpsilon2, mode, term)

% LFMGRADIENTH32 Gradient of the function h_i(z) with respect to some of the
%
%	Description:
%	hyperparameters of the kernel: m_k, C_k, D_k, m_r, C_r or D_r.
%
%	G = LFMGRADIENTH32(GAMMA1, GAMMA2, SIGMA2, GRADTHETAGAMMA, T1, T2,
%	MODE) Computes the gradient of the function h_i(z) with respect to
%	some of the parameters of the system (mass, spring or damper).
%	 Returns:
%	  G - Gradient of the function with respect to the desired
%	   parameter.
%	 Arguments:
%	  GAMMA1 - Gamma value for first system.
%	  GAMMA2 - Gamma value for second system.
%	  SIGMA2 - length scale of latent process.
%	  GRADTHETAGAMMA - Vector with the gradient of gamma1 and gamma2
%	   with respect to the desired parameter.
%	  T1 - first time input (number of time points x 1).
%	  T2 - second time input (number of time points x 1)
%	  MODE - indicates in which way the vectors t1 and t2 must be
%	   transposed
%	
%	
%
%	See also
%	LFMKERNGRADIENT, LFMXLFMKERNGRADIENT, LFMGRADIENTUPSILON


%	Copyright (c) 2007, 2008 David Luengo
%	Copyright (c) 2008 Mauricio Alvarez
% 	lfmGradientH32.m SVN version 100
% 	last update 2008-10-11T19:45:36.000000Z


% Gradient evaluation

if nargin<6
    term =[];
end

if ~mode
    if ~term
        g = compUpsilon1*(-(gradThetaGamma(2)/preFactor(2)) + (gradThetaGamma(1)/preFactor(1)));                
    else
        g = (compUpsilon1*preFactor(1) - conj(compUpsilon1)*preFactor(2))*gradThetaGamma;                  
    end
else
    g = compUpsilon1*(-(gradThetaGamma(2)/preFactor(3)) + (gradThetaGamma(1)/preFactor(1))) + ...
        compUpsilon2*(-(gradThetaGamma(1)/preFactor(2)) + (gradThetaGamma(2)/preFactor(4)));
end





