How to plot a function with 3 independent variables

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Seng Hkawn N-Sang 2021-10-13

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1562461-how-to-plot-a-function-with-3-independent-variables

评论： Seng Hkawn N-Sang 2021-10-15

采纳的回答： KSSV

f(x,y,z)=0.95*x+0.73*y+0.62*z-130.05

f(x,y,z); x; y; and z are values between 0 and 100.

f(x,y,z) is shown in color. How can I plot in MATLAB similar to figure below.

Thank you!

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Walter Roberson 2021-10-13

slice()

Or possibly isosurface() called several times

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采纳的回答

KSSV 2021-10-13

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1562461-how-to-plot-a-function-with-3-independent-variables#answer_807451

在 MATLAB Online 中打开

f = @(x,y,z) 0.95*x+0.73*y+0.62*z-130.05 ;
x = linspace(0,100) ;
y = linspace(0,100) ;
z = linspace(0,100) ; 
[X,Y,Z] = meshgrid(x,y,z) ; 
V = f(X,Y,Z) ; 
isosurface(X,Y,Z,V,1e-4)

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Walter Roberson 2021-10-14

在 MATLAB Online 中打开

f = @(x,y,z) 0.95*x+0.73*y+0.62*z-130.05 ;

x = linspace(60,100) ;

y = linspace(60,100) ;

z = linspace(60,100) ;

[X,Y,Z] = meshgrid(x,y,z) ;

V = f(X,Y,Z) ;

Vmin = min(V(:))

Vmin = 7.9500

Vmax = max(V(:))

Vmax = 99.9500

levels = 70:5:100;

Nlevels = length(levels);

cmap = hot(Nlevels);

for K = 1 : Nlevels

s = isosurface(X, Y, Z, V, levels(K));

p(K) = patch(s);

p(K).EdgeColor = 'none';

p(K).FaceColor = cmap(K,:);

isonormals(X, Y, Z, V, p(K));

end

camlight;

lighting gouraud;

xlim auto; ylim auto; zlim auto

view(3); view(36, 64);

legend(p, string(levels))

You cannot do contour lines because you are dealing with a 3D object: you can only do ISO surfaces.

It might be possible to get the colors right without some of the above steps. With the default steps I showed in https://www.mathworks.com/matlabcentral/answers/1562461-how-to-plot-a-function-with-3-independent-variables#comment_1783116 you might notice that the colors come out wrong compared to the legend: it turns out that you are looking at the "back" of the plates, and that you need to view() to see the front (or you need to move the light.)

Seng Hkawn N-Sang 2021-10-15