import data and plat a 3D
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I do have a excel file with 3 columns (x y z). I wanna import them to Matlab, and plot a nice surface Plot.i might have to interpolate?
2 个评论
Rik
2019-12-20
If it is a full grid of x and y, there will be no need for interpollation. Can you share your actual data, or a functional equivalent?
Verena Salan
2019-12-20
回答（2 个）
Rik
2019-12-20
No interpollation required, just a conversion to a 2D matrix. You can adapt the syntax of accumarray if you do have any missing values (by default it will fill with 0).
num=xlsread('test1.xlsx');
x=num(:,1);
y=num(:,2);
P=num(:,3);
%find the unique x and y values and use them as indices to fill the Z
[X,~,x_]=unique(x);
[Y,~,y_]=unique(y);
Z=accumarray([x_,y_],P);
[X,Y]=ndgrid(X,Y);
surf(X,Y,Z)
10 个评论
Verena Salan
2019-12-20
Verena Salan
2019-12-20
Rik
2019-12-20
The reshape method has the downside that you need to be sure about the orientation of your data. It will also fundamentally break if you don't have a complete grid.
Also note that surf will handle non-uniform spacing of values, it just needs a full grid (which is allowed to contain NaN values).
As to the question of how to get the volume: figure out a way to set the other hill to 0 and then use a 2D integration to find the volume.
Verena Salan
2020-1-2
Rik
2020-1-2
What have you tried?
Verena Salan
2020-1-6
Rik
2020-1-6
What have you tried so far?
Verena Salan
2020-1-6
Rik
2020-1-6
On a conceptual level, what would you do? If you needed to do it on paper, what would your approach be?
ME
2019-12-20
0 个投票
I think you are correct about the need to interpolate. You could try having a read of the link below - that should give you some good pointers.
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2019-12-20
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