How can I generate this plot?
I am trying to generate similar looking plots to the one attached. With this, do you know what kind of plot this is? And how to get the black bars showing where the orifice opening is?
John Michell answered .
2025-11-20
The quiver arrows all have fairly small magnitudes which makes it difficult to see the arrows but you can reproduce the figure and zoom in inspect parts of the image.
See inline comments for details.
% Load the data
data = load('average_vels.mat');
% Extract quiver variable for readability
x = data.output_avg(:,1);
y = data.output_avg(:,2);
u = data.output_avg(:,3);
v = data.output_avg(:,4);
% Compute signed magnitude of the quiver vectors where
% positive magnitudes point upward and neg mags point downward
z = hypot(u,v) .* sign(v);
% Reshape the z vector into a matrix where
% zMat(i,j) is the value at x=xVec(i) and y=yVec(j).
[xVec,~, zRow] = unique(x);
[yVec,~, zCol] = unique(y);
zMat = nan([numel(xVec),numel(yVec)]);
zIdx = sub2ind(size(zMat),zCol, zRow);
zMat(zIdx) = z;
% Plot the "heatmap" first
clf()
imagesc(xVec, yVec, zMat)
set(gca, 'YDir', 'Normal')
cbh = colorbar();
ylabel(cbh, 'Vector magnitude (positive is upward')
axis equal
% add the quiver data
hold on
quiver(x,y,u,v)