Rescale multiple spheres on the same 3d plot
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I am trying to plot multipe spheres of different sizes on the same 3D plot. I'd like the spheres placed closest to the origin to be the largest and the smallest ones furtherest away. I've tried sending a vector into the function function to control how many faces the sphere will have, but I get this error. The line numebrs in the error code don't match up exaclty because I have commented out my previous attempts at fixing the problem that don't apply.
Error in sphere (line 29)
cosphi = cos(phi); cosphi(1) = 0; cosphi(n+1) = 0;
Error in BioM3D_SphereTest>createspheres (line 83)
[x, y, z] = sphere(n);
Error in BioM3D_SphereTest (line 71)
[x_loc,y_loc,z_loc, spheresXYZ{i}] = createspheres(FNA_x(i),FNA_y(i),FNA_z(i), n(i,1));
Below is my code. Any help or ideas would be appreciated.
clear
close
clc
A = [0,0,0;0.00977495601952172,0.0129188554738323,0.999868768093125;-0.566794094824837,-0.823750570492204,0.0133959578031223;0.0279587435128966,0.0380588867245362,1.99938731654588;0.830388266617646,0.583999369869120,0.978401571089338;-1.07826433834531,-1.64452537544960,0.267810795303313;0.168715496407312,0.263085998125572,2.96351922435162;-0.791458202545459,0.611268411797120,0.998070417818667;-1.41124221175034,-0.289407593850698,0.0506110237693017;1.69942938355116,1.04462646221878,1.15892918358242;-1.55216375501531,-2.44987966243271,0.623934110066297;0.188310075544404,0.501770043093754,3.93441879647330;-1.44603145623221,1.35107113546187,1.15371676572365;-2.35391403973316,0.0183196401577155,0.179737992978120;2.59879677816763,1.38804628951095,1.42948622326796;-1.92629974765512,-3.28302931738291,1.03122259685150;0.190461468181228,0.731318108759712,4.90771374511875;-2.01837467713375,2.14014570650778,1.37684130228734;-3.30531517848174,0.217844651708771,0.414313445558867;3.50709118523837,1.65551615551852,1.75113998255253;-2.23204460424917,-4.13488361866807,1.45650407075820;0.193343935566412,0.934427321909631,5.88686559182864;-2.51244231909718,2.97180232130260,1.63030617210704;-4.25650570961388,0.357419056329789,0.689550723301627;4.41845060685608,1.87363023778730,2.10021053665969];
x = A(:, 1);
y = A(:, 2);
z = A(:, 3);
% Create Hemisphere Domain
[x_dom,y_dom,z_dom] = sphere(80); %Create Sphere
x_dom = x_dom(41:end,:); % Keep top 41 x points
y_dom = y_dom(41:end,:); % Keep top 41 y points
z_dom = z_dom(41:end,:); % Keep top 41 z points
hemisphere_radius = 80;
figure();
Hemi_sf = surf(hemisphere_radius.*x_dom,hemisphere_radius.*y_dom,hemisphere_radius.*z_dom, 'FaceColor','#4DBEEE','EdgeColor', 'none');
alpha 0.2 %Sets transparency of boundary hemisphere
axis equal
x_ax_lab = xlabel('x axis', 'Color', '#4DBEEE');
y_ax_lab = ylabel('y axis', 'Color', '#4DBEEE');
z_ax_lab = zlabel('z axis', 'Color', '#4DBEEE');
% Plot Outerboundary Circular Plane
x_c = 0;
y_c = 0;
z_c = 0;
radii_plane = 80;
radii_vein = 1;
center_plane = [x_c, y_c]; % center point of circular plane
viscircles(center_plane, radii_plane, 'color', '#77AC30');
hold on
SizeofA = size(A,1);
FNA_x = A(:, 1);
FNA_y = A(:, 2);
FNA_z = A(:, 3);
n = [6.96370042788934;5.96370042788934;5.96370042788934;4.96375547570639;5.55378214243664;4.97904924545806;3.98374650974911;5.55083110747708;5.52220023318542;4.65666303595053;3.99715084015465;2.99294670513842;4.67296636191766;4.60286314806927;3.68897172789716;3.02005588750933;1.99814346506139;3.71566225784534;3.62540440258680;2.70847851108481;2.04428077071202;1;2.74447376195869;2.63691531214705;1.72499063143428];
% Create Spheres
for i = 1:SizeofA
[x_loc,y_loc,z_loc, spheresXYZ{i}] = createspheres(FNA_x(i),FNA_y(i),FNA_z(i), n(i,1));
h(i) = surf(x_loc, y_loc, z_loc,'FaceColor', 'k');
end
function [X,Y,Z,spheresXYZ] = createspheres(spherex, spherey, spherez, n)
[x, y, z] = sphere(n);
X = (x+spherex);
Y = (y+spherey);
Z = (z+spherez);
spheresXYZ = [X,Y,Z];
end
Accepted Answer
On the first iteration of the i-loop, n equals 6.9637.... This value is passed to sphere(n) and, as the error message indicates,
Array indices must be positive integers or logical values.
n is not an integer. In the function sphere(n), n determines the size of the outpus which can be understood as the resolution of the sphere. Matrix sizes must be positive integers.
Demo 1
To scale the size of the unit-spheres produced by sphere(n), simply multiply the x,y,z outputs by a scaling factor.
[x,y,z] = sphere(20);
clf()
hold on
surf(x,y,z,'FaceColor','b','FaceAlpha',.5)
surf(x*2,y*2,z*2,'FaceColor','r','FaceAlpha',.2)
view(3)
axis equal
grid on
Demo 2
Scale the size of n randomly placed spheres based on their distance from (0,0,0), marked by a black +.
rng(999) % for reproducibility purposes
nSpheres = 10; % Number of spheres
maxEccentricity = 100; % max distance of sphere center from (0,0)
[x,y,z] = sphere(20);
clf()
colors = jet(nSpheres);
hold on
view(3)
grid on
box on
plot3(x,y,z,'k+')
for i = 1:nSpheres
az = rand(1)*2*pi;
el = rand(1)*pi - (pi/2);
radius = randi(maxEccentricity+1)-1;
[sx,sy,sz] = sph2cart(az,el,radius);
surf(x*radius/3+sx, y*radius/3+sy, z*radius/3+sz, 'FaceColor', 'interp', 'FaceAlpha', .6, 'EdgeAlpha',.3);
end
axis equal
view([-46.943, 11.247])
9 Comments
James Peach
on 5 Oct 2020
Adam Danz
on 5 Oct 2020
Yes, that's how you would scale the spheres.
But to create the sphere vertices you can't use n in sphere(n) since the values of n are not integers.
James Peach
on 13 Oct 2020
Adam Danz
on 13 Oct 2020
It's easiest if you're creating the spheres centered at (0,0,0), then resize them, and then shift them to the desired (x,y,z) coordinate by merely adding the x,y,z offsets that define their centers. Does that make sense?
James Peach
on 13 Oct 2020
Adam Danz
on 13 Oct 2020
Sounds good. Feel free to post the link to new but related questions as a comment here if you'd like to draw my attn to it.
James Peach
on 15 Oct 2020
Edited: James Peach
on 15 Oct 2020
Adam Danz
on 15 Oct 2020
" is there any way to clean the spheres up so that they are more distinct?"
You could use color
% Define colormap
cmap = jet(SizeofA);
for i = 1:SizeofA
[x_loc,y_loc,z_loc, spheresXYZ{i}] = createspheres(x(i),y(i),z(i), s(i));
h(i) = surf(x_loc+x(i), y_loc+y(i), z_loc+z(i), 'FaceColor', cmap(i,:), ...
'FaceAlpha', .5, 'EdgeColor', 'k', 'EdgeAlpha', .5);
end
And you could zoom into the spheres
xlim([min(Bx(:)),max(Bx(:))])
ylim([min(By(:)),max(By(:))])
zlim([min(Bz(:)),max(Bz(:))])
view([-43,38])
James Peach
on 15 Oct 2020
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