How to plot a 3D graph

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sophp 2018-1-31

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/380043-how-to-plot-a-3d-graph

评论： Star Strider 2018-1-31

I am attempting to plot a mesh 3D graph that displays how Y_B varies with t and T. I then want to solve this graph to find the coordinates that gives the maximum value of Y_B. This is the code to give a graph that displays how T varies with Y_B for different variables for t

if true
  % code
T=600:10:850;
t = 1;
k1 = 10^7.*exp(-12700./T);
k2 = 5*10^4.*exp(-10800./T);
k3 = 7*10^7.*exp(-15000./T);
t=1:2:20;
hold on;
for i=1:numel(t)
 Y_B = (k1.*t(i).*(k1+k3))./(((k2.*t(i))+1).*(k1+k3).*(1+(t(i).*(k1+k3))));
 plot(T,Y_B);
end

How do I transform this into a 3D plot for t = 0.2:20 and T = 600:850

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Star Strider 2018-1-31

What is ‘T’?

What is its range?

How does it enter into the calculation of ‘Y_B’?

sophp 2018-1-31

在 MATLAB Online 中打开

T changes the value of k1, k2 and k3

k1 = 10^7.*exp(-12700./T);
k2 = 5*10^4.*exp(-10800./T);
k3 = 7*10^7.*exp(-15000./T);

Its range is 600 to 850

Y_B is given by

Y_B = (k1.*t.*(k1+k3))./(((k2.*t+1).*(k1+k3).*(1+(t.*(k1+k3))));

The range of t is 0.2 to 20

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采纳的回答

Star Strider 2018-1-31

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/380043-how-to-plot-a-3d-graph#answer_302767

在 MATLAB Online 中打开

Use meshgrid to create matrices for ‘t’ and ‘T’, and remove the subscripts from the ‘Y_B’ calculation:

T=600:10:850;
t=1:2:20;
[tm,Tm] = meshgrid(t, T);
k1 = 10^7.*exp(-12700./Tm);
k2 = 5*10^4.*exp(-10800./Tm);
k3 = 7*10^7.*exp(-15000./Tm);
Y_B = (k1.*tm.*(k1+k3))./(((k2.*tm)+1).*(k1+k3).*(1+(tm.*(k1+k3))));
figure(1)
surf(t,T,Y_B)
grid on
xlabel('t')
ylabel('T')
zlabel('Y\_B')

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sophp 2018-1-31

I see. This works perfectly, how do I display these coordinates??

Star Strider 2018-1-31

在 MATLAB Online 中打开

I would do this:

DisplayCoordinates = [tm(Y_BmaxRow,Y_BmaxCol), Tm(Y_BmaxRow,Y_BmaxCol), Y_B(Y_BmaxRow,Y_BmaxCol)]
DisplayCoordinates =
    19.0000   710.0000   0.5114

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