problem with scatteredInterpolant: are there any limits?
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the xyz data file consists out of 3157394 data triples like this:
417826.974 5333045.048 1636.000
417826.974 5333045.128 1682.000
417826.974 5333045.208 1744.000
417826.974 5333045.288 1753.000
417826.974 5333045.368 1674.000
417826.974 5333045.448 1689.000
with the key data:
min(x) = 417740; max(x) = 417870; min(y) = 4177412; max(y)= 5333100; min(z)= 0; max(z) = 11054;
length(x) = length(y) = length(z) = 3157394;
First, everything works fine using:
TT=readtable(FileNameNeu,'PreserveVariableNames',true,'NumHeaderLines',1);
x=table2array(TT(:,1));
y=table2array(TT(:,2));
z=table2array(TT(:,3));
scatter3(x,y,z,4,z,'.'); view(2); grid on; daspect([1 1 1]);
But when I try this:
F = scatteredInterpolant(x,y,z,'natural','none'); :
[X,Y] = meshgrid(min(x):0.5:max(x),min(y):0.5:max(y));
Z = F(X,Y);
then I receive the error:
Error using scatteredInterpolant
The coordinates of the input points must be finite values; Inf and NaN are not
permitted.
Error in FillGaps (line 44)
F = scatteredInterpolant(x,y,z,'natural','none'); % create the interpolant
But...there are no Inf's and NaN's in the data file.
The same occurs if I reduce the values of x and z using:
x=x-min(x); y=y-min(y);
What I am doing wrong? Thanks a lot,
Harry
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채택된 답변
Star Strider
2022년 11월 13일
편집: Star Strider
2022년 11월 13일
It would help to have the file.
It appears to me that the data might be gridded. To determine that, the easiest way would be:
TT=readtable(FileNameNeu, 'VariableNamingRule','preserve')
x = TT{:,1};
y = TT{:,2};
z = TT{:,3};
[Ux,ixx] = unique(x)
RowSize = unique(ixx)
X = reshape(x,RowSize,[]);
Y = reshape(y,RowSize,[]);
Z = reshape(z,RowSize,[]);
figure
surf(X, Y, Z)
grid on
xlabel('X')
ylabel('Y')
zlabel('Z')
If that fails (the data not being gridded appropriately), try this —
L = size(TT,1);
xv = linspace(min(x), max(x), L);
yv = linspace(min(y), max(y), L);
[X,Y] = ndgrid(xv, yv);
Z = griddata(x, y, z, X, Y);
figure
surf(X, Y, Z)
grid on
xlabel('X')
ylabel('Y')
zlabel('Z')
One of those should work.
EDIT — (13 Nov 2022 at 23:52)
Corrected typographical errors.
.
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추가 답변 (1개)
Bruno Luong
2022년 11월 13일
You'll have problem anyway since your data is not centered and especially not normalize.
x range is 130 and y range is 1155688, almost 10000 larger than xrange. Scattered interpolation is based on Delauray triangulation, and that alone will give garbage out.
I believe it written somewhere (tip) this warning in the doc page.
So please do CENTERING and NORMALIZATION data as preproceesing step before interpoltion.
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