2d contourslice in a 3d domain in matlab

Question

i have a data file which contains the x,y,z coordinates of the variable V

x                   y   z                   V 
0                   0   0.500000000000000   3.91743717285931
0.0500000000000000  0   0.500000000000000   4.82593865902504
0.100000000000000   0   0.500000000000000   5.03874568425820
0.150000000000000   0   0.500000000000000   4.84015746128314
0.200000000000000   0   0.500000000000000   4.31320834211277
0.250000000000000   0   0.500000000000000   4.71007310928003
0.300000000000000   0   0.500000000000000   5.68353172300361
0.350000000000000   0   0.500000000000000   6.93907354201857
0.400000000000000   0   0.500000000000000   1.69713115593222
0.450000000000000   0   0.500000000000000   0
0.500000000000000   0   0.500000000000000   0
0.550000000000000   0   0.500000000000000   0
0.600000000000000   0   0.500000000000000   0.485840981213434
0.650000000000000   0   0.500000000000000   1.30265381445392
0.700000000000000   0   0.500000000000000   1.73892191516507
0.750000000000000   0   0.500000000000000   1.78720066586633
0.800000000000000   0   0.500000000000000   0.401158585618868
0.850000000000000   0   0.500000000000000   4.33700792828408
0.900000000000000   0   0.500000000000000   5.76388423361443
0.950000000000000   0   0.500000000000000   2.41835943394263

as the data file which contains the values are all in separate columns i am trying something this to convert the whole doamin into a single 3d doamin.

input = importdata('lci_000210.dat',' ',3);
nx = 96;
ny = 96;
nz = 49;

x = input.data(:,1);
y = input.data(:,2);
z = input.data(:,3);
Lci = input.data(:,4);


L3d = reshape(Lci,[nx,ny,nz]); 
x3d = reshape(x,[nx,ny,nz]);
y3d = reshape(y,[nx,ny,nz]);
z3d = reshape(z,[nx,ny,nz]);


[x3d,y3d,z3d,L3d] = flow;
xslice = 5;
yslice = 0;
zslice = 0;
slice(x,y,z,Lci,xslice,yslice,zslice);
view(25,20);
colormap jet
colorbar

this however keeps throwing up the following error

V must be a 3-D array.

So i am really unsure how to deal with the dataset, what i really would like is to take a slice at any location through the dataset, but still show the 3d doamin. i have attached a picture showing how i would like the slice to be represented. I have tried re-shape but that is not working, i jave done re-shape as the data is in columns and re-shape turns it into a 3d matrix as it should be.

The data is from a fluid flow simulation

Any advice and help will be extremely helpful on how to get the slices from this data set.

in the image it shows a contourslice at y=0, but i would like it to be shown at any y position, so the it can be seen where the slice has been taken from the full 3d picture

(https://www.dropbox.com/s/oqedi55q0qz7qv6/lci_000210.dat?dl=0) — Shahzad Muhammad Sarwar, Jul 27 '17 at 14:25

Gelliant · Accepted Answer · 2017-07-28T15:20:18.850

2

The problem seems to be your x3d and y3d are reversed.

slice(y3d,x3d,z3d,L3d,[],[],[0.1 0.3 0.5]);
ax=gca;
ax.Children(1).LineStyle='none';
ax.Children(2).LineStyle='none';
ax.Children(3).LineStyle='none';
view(25,20);
colormap jet
colorbar

For contours just give it a value to draw the contour of.

figure(2);clf
contourslice(y3d,x3d,z3d,L3d,[],[],[0.1 0.3 0.5],[10 20]);
view(25,20);

For contourplots I found a different solution. Not as straightforward as the other two.

zax = squeeze(z3d(1,1,:));
zvals=[2 13 24];
figure(1);clf;hold on
for ct = 1:length(zvals)
    %plot the contour
    contourf(L3d(:,:,zvals(ct)),[0 10 20]);
    ax=gca;
    ax.Children(1).XData=x3d(:,1,1); %set x axis
    ax.Children(1).YData=y3d(1,:,1); %set y axis
    ax.Children(1).ContourZLevel=zax(zvals(ct)); %put at correct z
end
view(25,20);colormap

Thanks to Amro's answer here: plot multiple 2d contour plots in one 3d figure [Matlab]

edited Jul 28 '17 at 15:20

answered Jul 27 '17 at 15:08

Gelliant

1,835
1
11
23

this is exactly what i need, the only thing is when adding 'contourslice' instead of just slice, how do i make the contourslices look like the plots when you use contourf – Shahzad Muhammad Sarwar Jul 27 '17 at 15:36
`contourslice(y3d,x3d,z3d,L3d,[],[],[0.1 0.3 0.5],[10 20]);` – Gelliant Jul 27 '17 at 15:58
i have just posted an image of how i want the contour to look. your answer so far has been excellent as it is what i need in terms of having multiple slices, but the final thing is to make it look like a filled contour – Shahzad Muhammad Sarwar Jul 28 '17 at 11:31
I see. That is indeed a bit more complicated, but the answer was already on stackoverflow. – Gelliant Jul 28 '17 at 15:17
Perfect, that is exactly what i need. – Shahzad Muhammad Sarwar Jul 29 '17 at 15:40
Could you mark the answer as correct? Then we can close this question. – Gelliant Jul 30 '17 at 16:08

score 1 · Answer 2 · answered Jul 28 '17 at 11:29

1

i just want something like this, so a filled contour.

answered Jul 28 '17 at 11:29

Shahzad Muhammad Sarwar

73
7

2d contourslice in a 3d domain in matlab

2 Answers2

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