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Hi Everyone,

I want to plot arrows with different magnitude and directions in different colors.The code need to calculate the angle of the each vector and fit them in the colormap.

This is what I have wrote but is there anyone that can help me to find the example or any other command or function in matlab that can plot this for me?

for i=1:40

structure(i,:,:)=rombohedral((i-1)*338+1:i*338,:);

X=structure(i,:,4);

Y=structure(i,:,5);

Z=structure(i,:,6);

U=structure(i,:,7);

V=structure(i,:,8);

W=structure(i,:,9);

C=zeros(338,3);

C(1:300,1)=1;

C(300:end,2)=1;

figure(i)

figure(i)

title('2D')

t=num2str(i);

xlabel([t,' ps'])

hold on

for j=1:338

if (U(j)>0)

quiver(X(j),Y(j),U(j),W(j),'color',[1 0 0])

elseif (U(j)<0)

quiver(X(j),Y(j),U(j),W(j),'color',[0 1 1])

elseif (V(j)>0)

quiver(X(j),Y(j),W(j),V(j),'color',[0 1 0])

elseif (V(j)<0)

quiver(X(j),Y(j),W(j),V(j),'color',[1 0 1])

end

end

end

Thorsten
on 11 Nov 2019

Create a circular colormap:

cmap = colormap(hsv(360));

In the loop: compute the angle and an index into the colormap from the angle

alpha = atan2(W(j), U(j)); % or V(j), W(j) depending on your elseif clause

Convert angle to index

idx = ceil(rad2deg(alpha));

if alpha < 1 % negative indices and 0 are invalid

idx = idx + 360;

end

set(h, 'Color', cmap(idx,:)) % before, change each quiver command to h = quiver(...)

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