How to plot this implicit function

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Atom 2019-9-8

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/479416-how-to-plot-this-implicit-function

评论： madhan ravi 2019-9-8

I need a beta vs eps plot of the curve t^2-d. The expression of t and d depends on x, y where x, y depend on beta. Please help. Ranges of beta and eps are both equal to 0:.01:1,

alpha=1.5; A=0.0207; gamma=0.25;
x=@(beta) (beta-alpha*(beta-gamma)+sqrt((beta-alpha*(beta-gamma)).^2+4*alpha*beta*gamma*A))./(2*beta);
y=@(beta) x.*(1-x).*beta/gamma;
t=@(beta,eps) -x+x.*y.*(alpha-eps*beta)./((A+x+y).^2);
d=@(beta,eps) eps*beta.*x.*y.*(x.^2+(A+x).*x+A*alpha)./((A+x+y).^3);
F=@(beta,eps) (t.^2-d);
figure
ezplot(F,[0,1,0,1]);

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Atom 2019-9-8

Inserted dot. still warning exists.

Warning: Function failed to evaluate on array inputs; vectorizing the function may speed up its evaluation and avoid the

need to loop over array elements.

> In ezplotfeval (line 56)

In ezplot>ezimplicit (line 257)

In ezplot (line 153)

In untitled1 (line 10)

darova 2019-9-8

Works for me

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采纳的回答

darova 2019-9-8

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/479416-how-to-plot-this-implicit-function#answer_390881

在 MATLAB Online 中打开

Try symbolic expression

clc,clear
alpha=1.5; A=0.0207; gamma=0.25;
syms beta eps
x = (beta-alpha*(beta-gamma)+sqrt((beta-alpha*(beta-gamma)).^2+4*alpha*beta*gamma*A))./(2*beta);
y =  x.*(1-x).*beta/gamma;
t =  -x+x.*y.*(alpha-eps*beta)./((A+x+y).^2);
d =  eps*beta.*x.*y.*(x.^2+(A+x).*x+A*alpha)./((A+x+y).^3);
    % convert symbolic expression to function handle
F = matlabFunction(t.^2 - d,'vars',[beta eps]);
ezplot(F,[0,1,0,1]);