Full surface from scatter by griddata!!!

A = [0.         0.         1.        
 0.         0.07124705 0.9974587 
 0.         0.15205718 0.9883717 
 0.         0.24253563 0.9701425 
 0.         0.34174306 0.93979342
 0.         0.4472136  0.89442719
 0.         0.5547002  0.83205029
 0.         0.65850461 0.75257669
 0.         0.75257669 0.65850461
 0.         0.83205029 0.5547002 
 0.         0.89442719 0.4472136 
 0.         0.93979342 0.34174306
 0.         0.9701425  0.24253563
 0.         0.9883717  0.15205718
 0.         0.9974587  0.07124705
 0.         1.         0.        
 0.07124705 0.         0.9974587 
 0.07647191 0.07647191 0.99413485
 0.08192319 0.16384638 0.9830783 
 0.08737041 0.26211122 0.96107446
 0.09245003 0.36980013 0.92450033
 0.09667365 0.48336824 0.87006284
 0.09950372 0.59702231 0.79602975
 0.10050378 0.70352647 0.70352647
 0.09950372 0.79602975 0.59702231
 0.09667365 0.87006284 0.48336824
 0.09245003 0.92450033 0.36980013
 0.08737041 0.96107446 0.26211122
 0.08192319 0.9830783  0.16384638
 0.07647191 0.99413485 0.07647191
 0.07124705 0.9974587  0.        
 0.15205718 0.         0.9883717 
 0.16384638 0.08192319 0.9830783 
 0.17609018 0.17609018 0.968496  
 0.18814417 0.28221626 0.94072087
 0.19900744 0.39801488 0.89553347
 0.20739034 0.51847585 0.82956136
 0.21199958 0.63599873 0.74199852
 0.21199958 0.74199852 0.63599873
 0.20739034 0.82956136 0.51847585
 0.19900744 0.89553347 0.39801488
 0.18814417 0.94072087 0.28221626
 0.17609018 0.968496   0.17609018
 0.16384638 0.9830783  0.08192319
 0.15205718 0.9883717  0.        
 0.24253563 0.         0.9701425 
 0.26211122 0.08737041 0.96107446
 0.28221626 0.18814417 0.94072087
 0.30151134 0.30151134 0.90453403
 0.31799936 0.42399915 0.8479983 
 0.32929278 0.5488213  0.76834982
 0.33333333 0.66666667 0.66666667
 0.32929278 0.76834982 0.5488213 
 0.31799936 0.8479983  0.42399915
 0.30151134 0.90453403 0.30151134
 0.28221626 0.94072087 0.18814417
 0.26211122 0.96107446 0.08737041
 0.24253563 0.9701425  0.        
 0.34174306 0.         0.93979342
 0.36980013 0.09245003 0.92450033
 0.39801488 0.19900744 0.89553347
 0.42399915 0.31799936 0.8479983 
 0.44444444 0.44444444 0.77777778
 0.45584231 0.56980288 0.68376346
 0.45584231 0.68376346 0.56980288
 0.44444444 0.77777778 0.44444444
 0.42399915 0.8479983  0.31799936
 0.39801488 0.89553347 0.19900744
 0.36980013 0.92450033 0.09245003
 0.34174306 0.93979342 0.        
 0.4472136  0.         0.89442719
 0.48336824 0.09667365 0.87006284
 0.51847585 0.20739034 0.82956136
 0.5488213  0.32929278 0.76834982
 0.56980288 0.45584231 0.68376346
 0.57735027 0.57735027 0.57735027
 0.56980288 0.68376346 0.45584231
 0.5488213  0.76834982 0.32929278
 0.51847585 0.82956136 0.20739034
 0.48336824 0.87006284 0.09667365
 0.4472136  0.89442719 0.        
 0.5547002  0.         0.83205029
 0.59702231 0.09950372 0.79602975
 0.63599873 0.21199958 0.74199852
 0.66666667 0.33333333 0.66666667
 0.68376346 0.45584231 0.56980288
 0.68376346 0.56980288 0.45584231
 0.66666667 0.66666667 0.33333333
 0.63599873 0.74199852 0.21199958
 0.59702231 0.79602975 0.09950372
 0.5547002  0.83205029 0.        
 0.65850461 0.         0.75257669
 0.70352647 0.10050378 0.70352647
 0.74199852 0.21199958 0.63599873
 0.76834982 0.32929278 0.5488213 
 0.77777778 0.44444444 0.44444444
 0.76834982 0.5488213  0.32929278
 0.74199852 0.63599873 0.21199958
 0.70352647 0.70352647 0.10050378
 0.65850461 0.75257669 0.        
 0.75257669 0.         0.65850461
 0.79602975 0.09950372 0.59702231
 0.82956136 0.20739034 0.51847585
 0.8479983  0.31799936 0.42399915
 0.8479983  0.42399915 0.31799936
 0.82956136 0.51847585 0.20739034
 0.79602975 0.59702231 0.09950372
 0.75257669 0.65850461 0.        
 0.83205029 0.         0.5547002 
 0.87006284 0.09667365 0.48336824
 0.89553347 0.19900744 0.39801488
 0.90453403 0.30151134 0.30151134
 0.89553347 0.39801488 0.19900744
 0.87006284 0.48336824 0.09667365
 0.83205029 0.5547002  0.        
 0.89442719 0.         0.4472136 
 0.92450033 0.09245003 0.36980013
 0.94072087 0.18814417 0.28221626
 0.94072087 0.28221626 0.18814417
 0.92450033 0.36980013 0.09245003
 0.89442719 0.4472136  0.        
 0.93979342 0.         0.34174306
 0.96107446 0.08737041 0.26211122
 0.968496   0.17609018 0.17609018
 0.96107446 0.26211122 0.08737041
 0.93979342 0.34174306 0.        
 0.9701425  0.         0.24253563
 0.9830783  0.08192319 0.16384638
 0.9830783  0.16384638 0.08192319
 0.9701425  0.24253563 0.        
 0.9883717  0.         0.15205718
 0.99413485 0.07647191 0.07647191
 0.9883717  0.15205718 0.        
 0.9974587  0.         0.07124705
 0.9974587  0.07124705 0.        
 1.         0.         0.        ];

x = A(:,1);
y = A(:,2);
z = A(:,3);
[xq,yq] = meshgrid(0:.01:1);
vq = griddata(x,y,z,xq,yq,'linear');
mesh(xq,yq,vq)
hold on
scatter3(x,y,z,'filled')
view(135,45)

This is picture I get: (Figure 1)

This is picture I want to get:(Figure 2)

The line above is code I try to run full surface but I only get (figure(1)) The edge in bottom do not have. So how can i get Full surface like this from this code. Any other solution in this case??? Thank you.

Answer 1

[Bjorn Gustavsson]

This is "just" a pixellation-problem. You can see how it comes about by varying the resolution of your grid:

[xq,yq] = meshgrid(0:.001:1);
vq = griddata(x,y,z,xq,yq,'linear');
subplot(2,2,1)
surf(xq,yq,vq),shading flat
view(0,90)
hold on
scatter3(x,y,z,8,'r','filled')
subplot(2,2,2)
[xq,yq] = meshgrid(0:.01:1);
vq = griddata(x,y,z,xq,yq,'linear');
surf(xq,yq,vq),shading flat
view(0,90)
hold on
scatter3(x,y,z,8,'r','filled')
subplot(2,2,3)
[xq,yq] = meshgrid(0:.1:1);
vq = griddata(x,y,z,xq,yq,'linear');
surf(xq,yq,vq),shading flat
view(0,90)
hold on
scatter3(x,y,z,8,'r','filled')

Alternatively you could use trisurf:

tri = delaunay(x,y);
tr = triangulation(tri, x(:), y(:), z(:));
subplot(2,2,4)
trisurf(tr)
view(0,90)
shading flat

HTH

[Le Xuan Thang]

Oh! thank you so much for solution by trisuft. this is exactly what i need.

[Le Xuan Thang]

That would be great if you explain to me that how your code work.

[Bjorn Gustavsson]

These are all matlab-provided functions, so for full documentation just check the help and online-docs. The delaunay-function does a delaunay-triangulation of your points. The call to triangulate is just to add the z-component to the triangulation, and the trisurf call I got from the example in the trisurf help.

[Le Xuan Thang]

Oh i see. Thank you a lot