如何将下边maole中的代码改为matlabfig:=proc(P_x,P_y,P_z,R,mu,varphi,C) with(plots);with(ColorTools); local Rb; local Rf := implicitplot(x^2 + y^2 = R^2, x = -R .. R, y = -R .. 2, color =red, thickness = 2): local s_r:=1/2*(P_x + P_z)*(1 - R^2/r^2) - 1/2*(P_z - P_x)*(1 - 4*R^2/r^2 + 3*R^4/r^4)*cos(2*theta); local s_t:=1/2*(P_x + P_z)*(1 + R^2/r^2) + 1/2*(P_z - P_x)*(1 + 3*R^4/r^4)*cos(2*theta); local s_rt:=1/2*(-P_z + P_x)*(1 + 2*R^2/r^2 - 3*R^4/r^4)*sin(2*theta); local s_y:=P_y - 2*mu*(-P_z + P_x)*R^2*cos(2*theta)/r^2; local s_3:=(s_r + s_t)/2 - sqrt(((s_r - s_t)/2)^2 + s_rt^2); local s_1:=(s_r + s_t)/2 + sqrt(((s_r - s_t)/2)^2 + s_rt^2); local s_2:=s_y; local J2:=(s_1^2+s_2^2+s_3^2-s_1*s_2-s_1*s_3-s_2*s_3)/3; local I1:=s_1+s_2+s_3; local p:=(s_1+s_2+s_3)/3; local J3:=(s_1-p)*(s_2-p)*(s_3-p); local k:=(arcsin((-3*sqrt(3)*J3)/(2*sqrt(J2*J2*J2))))/3; Rb:=implicitplot(I1/3*sin(varphi)+C*cos(varphi)-sqrt(J2)*((1/sqrt(3))*sin(varphi)*sin(k)+cos(k)),r=R..R*20,theta=0..2*Pi,coords=polar,thickness=2); display(Rf,Rb) end proc:

以下是将maole中的代码改为MATLAB的代码，MATLAB中没有ColorTools模块，因此省略相关部分：

function matlabfig = proc(P_x, P_y, P_z, R, mu, varphi, C)
    syms r theta;
    Rf = ezplot(r^2*cos(theta)^2 + r^2*sin(theta)^2 - R^2 == 0, [-R, R, -R, 2]);
    set(Rf, 'Color', 'red', 'LineWidth', 2);
    s_r = 1/2*(P_x + P_z)*(1 - R^2/r^2) - 1/2*(P_z - P_x)*(1 - 4*R^2/r^2 + 3*R^4/r^4)*cos(2*theta);
    s_t = 1/2*(P_x + P_z)*(1 + R^2/r^2) + 1/2*(P_z - P_x)*(1 + 3*R^4/r^4)*cos(2*theta);
    s_rt = 1/2*(-P_z + P_x)*(1 + 2*R^2/r^2 - 3*R^4/r^4)*sin(2*theta);
    s_y = P_y - 2*mu*(-P_z + P_x)*R^2*cos(2*theta)/r^2;
    s_3 = (s_r + s_t)/2 - sqrt(((s_r - s_t)/2)^2 + s_rt^2);
    s_1 = (s_r + s_t)/2 + sqrt(((s_r - s_t)/2)^2 + s_rt^2);
    s_2 = s_y;
    J2 = (s_1^2+s_2^2+s_3^2-s_1*s_2-s_1*s_3-s_2*s_3)/3;
    I1 = s_1+s_2+s_3;
    p = (s_1+s_2+s_3)/3;
    J3 = (s_1-p)*(s_2-p)*(s_3-p);
    k = (asin((-3*sqrt(3)*J3)/(2*sqrt(J2^2*J2))))/3;
    Rb = ezplot(I1/3*sin(varphi)+C*cos(varphi)-sqrt(J2)*((1/sqrt(3))*sin(varphi)*sin(k)+cos(k)), [R, R*20, 0, 2*pi]);
    set(Rb, 'LineWidth', 2);
    matlabfig = [Rf, Rb];
end