How do I make surf accurately reflect my data?

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Henrik 2014-11-18

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https://ww2.mathworks.cn/matlabcentral/answers/163284-how-do-i-make-surf-accurately-reflect-my-data

评论： Henrik 2014-11-23

Consider this example:

A=zeros(5);
A(3,3)=1;
surf(A)
view(2)

When viewing this, one would be tempted to think that there's a peak at (3.5,3.5) and not at (3,3). Is there a way to make surf (or another function) show the right color exactly where the peak is?

Of course I want to implement this for more complicated data sets, so a general solution would be very nice.

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Answer 1

Orion 2014-11-18

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https://ww2.mathworks.cn/matlabcentral/answers/163284-how-do-i-make-surf-accurately-reflect-my-data#answer_159421

在 MATLAB Online 中打开

you can play with shading

A=zeros(5);
A(3,3)=1;
surf(A);
pause(1)
view(2);
pause(1)
shading interp

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Mike Garrity 2014-11-19

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Actually using FaceColor=texturemap works here.

A=zeros(5);
A(3,3)=1;
surf(A,'FaceColor','texturemap')
view(2)

What's happening in the FaceColor=flat case is that it's mapping the first 4x4 of the CData to the entire range of XData & YData. It has to do that because a 5x5 grid of XData & YData yields a 4x4 grid of quads.

But with FaceColor=texture, we're mapping the entire 5x5 contents of the CData to the 5x5 range of XData & YData. It can do that because texturemap doesn't have to assign one color per quad. It can split colors across quads so it can do any mapping. You could map a 7x5 CData onto a 3x4 XData & YData if you wanted to. So it gives you a lot of flexibility, but it will also let you make a mess if you're not careful.

Henrik 2014-11-23