Problem with contourf for scattered data
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Hello!
I have a table with 3 columns (x,y,value) for scattered data from the image like this.
But when I take griddata and then contouf, I get such a plot with strange netted area (in the bottom). Blue points are my sctttered data
Area in the bottom large (small bubbles):
So the question is what am i doing wrong? Why do I get these netted areas instead of great filled areas? Why i get it i these places and others are ok&
Listing of my code, table in attachments
[xq,yq] = meshgrid(0:1:3550, 0:1:2550); % interpolation points grid
vq = griddata(x,y,values,xq,yq,'natural');
Z = squeeze(vq);
grid on
[hq,hqlbl] = contourf(xq,yq,Z);
clabel(hq,hqlbl)
colorbar ('Direction','reverse')
caxis([-60 20])
2 个评论
Cris LaPierre
2019-5-15
编辑：Cris LaPierre
2019-5-15
Which column contains value? Your spreadsheet has 10 columns in it. X and Y are obvious, but not sure what you want to use for elevation.
Perhaps you could describe what it is you are trying to do? If you could explain what you want your final result to be, we can better help you decide what it is you should do.
Cyril Basalaev
2019-5-15
采纳的回答
Cris LaPierre
2019-5-15
编辑：Cris LaPierre
2019-5-15
I didn't look into what is causing it, but inspecting Z has me thinking it might be roundoff error. Your Z values in this region are varying between 1 and 1.0000. Since your contour line is for Z==1, I suspect it is trying to create a contour line around each 1.0000 "island".
I was able to clear it up for the 1/23/2017 data by adding round to the following code:
Z = squeeze(round(vq,4));
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