anchor.diff:  		real(kind=8), dimension(:), intent(in) :: x1, x2
   		real(kind=8), dimension(size(x1), size(x2)) :: matrix
   
  -		if (size(self%pars) /= 2) STOP 'Wrong parameter dimension - ExpSquaredKernel(2 hyper)'
  -		! pars(1) --> amplitude
  -		! pars(2) --> lengthscale
  +		if (size(self%pars) /= 1) STOP 'Wrong parameter dimension - ExpSquaredKernel(1 hyper)'
  +		! pars(1) --> lengthscale
   		matrix = 0.d0
   		matrix = get_radial_coordinates(x1, x2)
  -		matrix = self%pars(1) * exp(-0.5d0 * (matrix / self%pars(2))**2)
  +		matrix = exp(-0.5d0 * (matrix / self%pars(1))**2)
   
   	end function evaluate_kernel_ExpSquaredKernel
   
  
positive.code: 		!procedure(evaluate_kernel), pointer :: get_matrix_pointer => NULL()
  		procedure :: evaluate_kernel
  		procedure :: sample_prior
  		!procedure :: add_kernel_to_kernel
  		!generic :: operator(+) => add_kernel_to_kernel
  	end type Kernel
  
negative.code: 		!class(Kernel), pointer :: kernel5 => NULL()
  	contains
  		procedure :: evaluate_kernel => evaluate_kernel_sum
  		procedure :: set_kernel_pars => set_sub_kernel_pars_sum
  		procedure :: get_kernel_pars => get_sub_kernel_pars_sum
  	end type SumKernels
  
  	! Product of kernels
  