You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: computeParametrizationGradient.m
    path of file: ./repos/whole-body-controllers/controllers/floating-base-jerk-control/src/parametrization
    
    the code of the file until where you have to start completion: function Beta = computeParametrizationGradient(xi, Config)

    % delta feet size
    delta_x   =  (Config.feet_size(2,2) - Config.feet_size(2,1))/2;
    delta_x_0 = -(Config.feet_size(2,2) + Config.feet_size(2,1))/2;
    delta_y   =  (Config.feet_size(1,2) - Config.feet_size(1,1))/2;
    delta_y_0 =  (Config.feet_size(1,2) + Config.feet_size(1,1))/2;
    
    % initialize Beta and Fz
    Beta      = zeros(6);
    Fz        = exp(xi(3)) + Config.fZmin;
    
    % add non-zero elements
    
    % df/dxi_1
    Beta(1,1) =  sqrt(Config.forceFrictionCoefficient)*(1 - tanh(xi(1))^2)*Fz/sqrt(1 + tanh(xi(2))^2);
    Beta(2,1) = -sqrt(Config.forceFrictionCoefficient)*tanh(xi(2))*Fz/(1 + tanh(xi(1))^2)^(3/2)*tanh(xi(1))*(1 - tanh(xi(1))^2);
    
    % df/dxi_2
    Beta(1,2) = -sqrt(Config.forceFrictionCoefficient)*tanh(xi(1))*Fz/(1 + tanh(xi(2))^2)^(3/2)*tanh(xi(2))*(1 - tanh(xi(2))^2);
    Beta(2,2) =  sqrt(Config.forceFrictionCoefficient)*(1 - tanh(xi(2))^2)*Fz/sqrt(1 + tanh(xi(1))^2);
    
    % df/dxi_3
    Beta(1,3) = sqrt(Config.forceFrictionCoefficient)*tanh(xi(1))*exp(xi(3))/sqrt(1 + tanh(xi(2))^2);

    
function Beta = computeParametrizationGradient(xi, Config)

    % delta feet size
    delta_x   =  (Config.feet_size(2,2) - Config.feet_size(2,1))/2;
    delta_x_0 = -(Config.feet_size(2,2) + Config.feet_size(2,1))/2;
    delta_y   =  (Config.feet_size(1,2) - Config.feet_size(1,1))/2;
    delta_y_0 =  (Config.feet_size(1,2) + Config.feet_size(1,1))/2;
    
    % initialize Beta and Fz
    Beta      = zeros(6);
    Fz        = exp(xi(3)) + Config.fZmin;
    
    % add non-zero elements
    
    % df/dxi_1
    Beta(1,1) =  sqrt(Config.forceFrictionCoefficient)*(1 - tanh(xi(1))^2)*Fz/sqrt(1 + tanh(xi(2))^2);
    Beta(2,1) = -sqrt(Config.forceFrictionCoefficient)*tanh(xi(2))*Fz/(1 + tanh(xi(1))^2)^(3/2)*tanh(xi(1))*(1 - tanh(xi(1))^2);
    
    % df/dxi_2
    Beta(1,2) = -sqrt(Config.forceFrictionCoefficient)*tanh(xi(1))*Fz/(1 + tanh(xi(2))^2)^(3/2)*tanh(xi(2))*(1 - tanh(xi(2))^2);
    Beta(2,2) =  sqrt(Config.forceFrictionCoefficient)*(1 - tanh(xi(2))^2)*Fz/sqrt(1 + tanh(xi(1))^2);
    
    % df/dxi_3
    Beta(1,3) = sqrt(Config.forceFrictionCoefficient)*tanh(xi(1))*exp(xi(3))/sqrt(1 + tanh(xi(2))^2);
    Beta(2,3) = sqrt(Config.forceFrictionCoefficient)*tanh(xi(2))*exp(xi(3))/sqrt(1 + tanh(xi(1))^2);
    Beta(3,3) = exp(xi(3));
    Beta(4,3) = (delta_x*tanh(xi(4)) + delta_x_0)*exp(xi(3));
    Beta(5,3) = (delta_y*tanh(xi(5)) + delta_y_0)*exp(xi(3));
    Beta(6,3) = Config.torsionalFrictionCoefficient*tanh(xi(6))*exp(xi(3));
    
    % df/dxi_4
    Beta(4,4) = delta_x*(1 - tanh(xi(4))^2)*Fz;
    
    % df/dxi_5
    Beta(5,5) = delta_y*(1 - tanh(xi(5))^2)*Fz;
    
    % df/dxi_6
    Beta(6,6) = Config.torsionalFrictionCoefficient*(1 - tanh(xi(6))^2)*Fz;  
end