How to do interpolation in matlab??
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I have attached an excel file, which contains x, y, z data. I want to interpolate the data. Can you help?? (In the data for a particular x at different y value, the z value is different. )
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Star Strider
2021-2-4
I am not absolutely certain what you want to do.
The row lengths between unique values in the first column are not the same, so using reshape is not an option to create matrices from the data.
One option, if you want to create a uniformly-sampled matrix, is to use griddata to do the interpolation:
D = readmatrix('data.xlsx');
[Du,ia] = unique(D(:,1));
rowlen = diff(ia); % Changes In ‘x’
xv = linspace(min(D(:,1)), max(D(:,1)), 50);
yv = linspace(min(D(:,2)), max(D(:,2)), 50);
[X,Y] = ndgrid(xv,yv);
Z = griddata(D(:,1), D(:,2),D(:,3),X,Y);
figure
surf(X, Y, Z)
This also plots the result.
Change the code appropriately to get the result you want.
8 个评论
TAPAS
2021-2-4
TAPAS
2021-2-4
TAPAS
2021-2-4
Star Strider
2021-2-4
It was not initially obvious what result you wanted.
It is straightforward to change the resolution of the interpolation:
N = 250;
xv = linspace(min(D(:,1)), max(D(:,1)), N);
yv = linspace(min(D(:,2)), max(D(:,2)), N);
[X,Y] = ndgrid(xv,yv);
Z = griddata(D(:,1), D(:,2),D(:,3),X,Y);
With respect to plotting, one option:
figure
surf(X, Y, Z)
shading('interp')
view(0,90)
contourf(X, Y, Z, 'EdgeColor','none')
Experiment to get the result you want.
TAPAS
2021-2-5
TAPAS
2021-2-5
Star Strider
2021-2-5
As always, my pleasure!
I am not certain what to suggest with respect to getting all the information you want from your data, since I am not certain what that is.
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