Plotting streamlines in matlab.

I am trying plot streamlines using the streamlinefunction. The number of streamlines i'm getting streamlines are way too less. I am attaching the code and the data file containing the velocity components and their co-ordinates. please help me in resolving the issue.

Answer 1

[darova]

Just increased number of starting points

n = 100;                 % number of streamlines
starting_x = zeros(1,n); % starting points for streamlines
starting_y = linspace(-0.1,0.1,n);

[darova]

Deleted first row (at the beginning of the code):

velcomppos(1,:) = [];

And got:

[Naveen K S]

After your suggestion i have edited the code as below. But I'm getting streamlines like in the attached file

mag_V = sqrt( velcomppos.Vx.^2 + velcomppos.Vy.^2);
    % Filtering out zero velocity walls.
   index = mag_V > 0.01;
    xx = velcomppos.x(index);
    yy = velcomppos.y(index);
    Vxx = velcomppos.Vx(index);
    Vyy = velcomppos.Vy(index);
    FVx = scatteredInterpolant(xx,yy,Vxx,'linear','none');
    FVy = scatteredInterpolant(xx,yy,Vyy,'linear','none');
    %FVz = scatteredInterpolant(xx,yy,zz,Vzz,'linear','none');
    % This is a very ugly grid for your problem but it works.
    % A cylindrical grid would probably be more resource efficient
    elements = 78; % how many subdivisions per dimensions.
    % Mind you, this is 3D. Total memory gets large fast
    [X3, Y3] = meshgrid(linspace(min(velcomppos.x),max(velcomppos.x),elements),...
        linspace(min(velcomppos.y),max(velcomppos.y),elements));
        %linspace(min(velcomppos.z),max(velcomppos.z),elements));
    V3x = FVx(X3,Y3);
    V3y = FVy(X3,Y3);
    %V3z = FVz(X3,Y3);
    mag_V3 = sqrt(V3x.^2 + V3y.^2); % velocity vector magnitude
    n=100;
    starting_x = zeros(1,n); % starting points for streamlines
    starting_y = linspace(-0.1,0.1,n);
    %[starting_y] = meshgrid(linspace(-0.007,.007,7));
        (linspace(-0.1,.1,n));
    figure(1)
    clf
    %plot(velcomppos.x,velcomppos.y,'.k','MarkerSize',1);
    hold on
    %quiver(velcomppos.x,velcomppos.y,velcomppos.Vx,velcomppos.Vy);
    %h = slice(X3,Y3,mag_V3,[],0,-0.02:.02:0);
    %set(h,'EdgeColor','w','FaceAlpha',0.75');
    streamline(X3,Y3,V3x,V3y,starting_x,starting_y);
    %set(h,'color','r','LineWidth',4);
    axis ([ 0.170 0.35 -0.1 0.07])
    grid on
    hold on
    xlabel('x');
    ylabel('y');
     set(get(gca,'YLabel'),'Rotation',0);
     
     

[darova]

Delete first row of your data (it's defective)

and change axis boundaries

axis ([ xmin xmax ymin ymax])