Matlab隐函数求导作图

主程序main.m

close
clc
clear
syms x y
x=0:0.01:2*pi;
y=solve('(3.6*cos(x)+17*cos(y)+1)^2+(3.6*sin(x)+17*sin(y)-16.5)^2-36=0','y');
y=subs(y);

n=length(y)
for i=1:1:2
    for j=1:1:n
        if(~isreal(y(i,j)))
            y(i,j)=0;
        end
    end
end

x1=x;
y1=y(1,:);
x1(y1==0)=[]
y1(y1==0)=[]
omg1= omega(x1,y1)
plot(x1,y1,'*')
grid on
figure

x2=x
y2=y(2,:)
x2(y2==0)=[]
y2(y2==0)=[]
omg2=omega(x2,y2)
plot(x2,y2,'*')
grid on
figure

plot(x1,omg1,'.',x2,omg2,'.')
grid on

omega函数：

function [omg]=omega(x,y)
%caculate omega
A=3.6*cos(x)+17*cos(y)+1
B=3.6*sin(x)+17*sin(y)-16.5
omg=3.6/17*(B.*cos(x)-A.*sin(x)) ./ (A.*sin(y)-B.*cos(y))
end