MATLAB: How to make a selection of the streamlines

meshgridstreamline

Hi everybody,
I use the command Streamlines to simulate the stream-flow of water in a porous media 3D. Now I want to view only the lines that crossing completely the cube (from left to right). How can I do?
Here it is the code I used
[sx,sy,sz]=meshgrid(10:5:nx-10,10:5:nx-10,10:5:nz-10);
hlines=streamline(1:nx,1:ny,1:nz,uy,ux,uz,sy,sx,sz);
set(hlines,'linewidth',2,'color','r')

Best Answer

Try running the code below. It plots all streamlines, then loops through each streamline asking, "does this streamline's x data pass through 85 and 130?" If yes, it changes the streamlines to red.
load wind
[sx,sy,sz] = meshgrid(80,20:10:50,0:5:15);
h = streamline(x,y,z,u,v,w,sx,sy,sz);
view(3) 
xlabel('x direction') 
ylabel('y direction') 
% preallocate an array of streamline indices that we'll later deem
% interesting:
ind = zeros(size(h));
for k = 1:length(h); % essentially, for each stream line.
    xk = get(h(k),'xdata'); % get its x data
    if min(xk)<=85 & max(xk)>=130; 
        ind(k)=1; 
    end    
end
% set qualifying streamlines to red.
set(h(logical(ind)),'color','red')
You could similarly delete non-qualifying streamlines with
delete(h(~logical(ind)))
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