non square matrix interpolation matlab (colorgraph)

2022 6 8
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更新时间：2022 6 9
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I need help to interpolate non-square matrices in my code, because the code I have been working on works only for square matrices.
Thank you
clc; clear; close all;
V = [600.1 645.23 865.17 1425.8 1254.4;
1012.1 1055.8 1006.3 1537.1 1212;
1296.6 1616.6 1351.9 1393.5 1391.9;
639.5 868.24 890.56 1644.9 1770.8;
639.5 868.24 890.56 1644.9 1770.8];
ecol = 30;
ncol = 5 ;
efil = 30;
nfil = 5 ;
%% Matriz de valores para la interpolación del paño
x = (0:ecol:(ncol-1)*ecol);
for i = 1:ncol
X(i,:)= x;
end
y = (0:efil:(nfil-1)*efil)';
for k = 1:nfil
Y(:,k)= y;
end
x = (0:1:(ncol-1)*ecol);
for i = 1:(nfil-1)*efil + 1
Xq(i,:)= x;
end
y = (0:1:(nfil-1)*efil)';
for k = 1:(ncol-1)*ecol + 1
Yq(:,k)= y;
end
M1q = interp2(X,Y,V,Xq,Yq,'cubic');
%% Ploteo del mapa de velocidades
figure('units','normalized','outerposition',[0 0 1 1])
s = contourf(Xq,Yq,M1q,'--','showtext', 'on');
view(2)
colorbar
set(gca,'Ydir','reverse');
axis tight
title("ST1 [m/s]", 'Fontsize', 15, 'Fontname', 'Times New Roman')
xlabel("Horizontal Displacement [cm]", 'Fontsize', 15, 'Fontname', 'Times New Roman')
ylabel("Vertical Displacement [cm]", 'Fontsize', 15, 'Fontname', 'Times New Roman')

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Voss
Voss 2022-6-8
编辑：Voss 2022-6-8
Ran in:

2 个投票

Ran in:
There is an error in how your matrices X and Y are constructed: nfil and ncol are swapped in those two for loops. It's corrected here:
clc; clear; close all;
V = [600.1 645.23 865.17 1425.8 1254.4;
1012.1 1055.8 1006.3 1537.1 1212;
1296.6 1616.6 1351.9 1393.5 1391.9;
...639.5 868.24 890.56 1644.9 1770.8;
639.5 868.24 890.56 1644.9 1770.8];
ecol = 30;
efil = 30;
[nfil,ncol] = size(V); % avoid hard-coding nfil and ncol; get them from size(V) instead
%% Matriz de valores para la interpolación del paño
x = (0:ecol:(ncol-1)*ecol); % x = (0:ncol-1)*ecol; % would be better
for i = 1:nfil % this was ncol
X(i,:)= x;
end
y = (0:efil:(nfil-1)*efil)'; % y = (0:nfil-1).'*efil; % would be better
for k = 1:ncol % this was nfil
Y(:,k)= y;
end
disp(X); disp(Y);
0 30 60 90 120 0 30 60 90 120 0 30 60 90 120 0 30 60 90 120 0 0 0 0 0 30 30 30 30 30 60 60 60 60 60 90 90 90 90 90
Note that you can use the meshgrid function to construct X and Y the same way.
[X,Y] = meshgrid(x,y);
disp(X); disp(Y);
0 30 60 90 120 0 30 60 90 120 0 30 60 90 120 0 30 60 90 120 0 0 0 0 0 30 30 30 30 30 60 60 60 60 60 90 90 90 90 90
x = (0:1:(ncol-1)*ecol);
for i = 1:(nfil-1)*efil + 1 % could use Xq = repmat(x,nfil,1); instead of a loop
Xq(i,:)= x;
end
y = (0:1:(nfil-1)*efil)';
for k = 1:(ncol-1)*ecol + 1 % could use Yq = repmat(y,1,ncol); instead of a loop
Yq(:,k)= y;
end
M1q = interp2(X,Y,V,Xq,Yq,'cubic');
%% Ploteo del mapa de velocidades
figure('units','normalized','outerposition',[0 0 1 1])
s = contourf(Xq,Yq,M1q,'--','showtext', 'on');
view(2)
colorbar
set(gca,'Ydir','reverse');
axis tight
title("ST1 [m/s]", 'Fontsize', 15, 'Fontname', 'Times New Roman')
xlabel("Horizontal Displacement [cm]", 'Fontsize', 15, 'Fontname', 'Times New Roman')
ylabel("Vertical Displacement [cm]", 'Fontsize', 15, 'Fontname', 'Times New Roman')

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Stephen23
Stephen23 2022-6-8
Xq and Yq should also be replaced by MESHGRID. All of the loops are superfluous and inefficient.
Dear thank you for your help
you saved me a week of doubts

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