# 3D Cone Plots in MATLAB®

How to make 3D Cone Plots plots in MATLAB® with Plotly.

## 3-D Cone Plot

Plot velocity vector cones for vector volume data representing motion of air through a rectangular region of space.

Load the data. The wind data set contains the arrays u, v, and w that specify the vector components and the arrays x, y, and z that specify the coordinates.

load wind



Establish the range of the data to place the slice planes and to specify where you want the cone plots.

load wind

xmin = min(x(:));
xmax = max(x(:));
ymin = min(y(:));
ymax = max(y(:));
zmin = min(z(:));


Define where to plot the cones. Select the full range in x and y and select the range 3 to 15 in z.

load wind

xmin = min(x(:));
xmax = max(x(:));
ymin = min(y(:));
ymax = max(y(:));
zmin = min(z(:));

xrange = linspace(xmin,xmax,8);
yrange = linspace(ymin,ymax,8);
zrange = 3:4:15;
[cx,cy,cz] = meshgrid(xrange,yrange,zrange);


Plot the cones and set the scale factor to 5 to make the cones larger than the default size.

load wind

xmin = min(x(:));
xmax = max(x(:));
ymin = min(y(:));
ymax = max(y(:));
zmin = min(z(:));

xrange = linspace(xmin,xmax,8);
yrange = linspace(ymin,ymax,8);
zrange = 3:4:15;
[cx,cy,cz] = meshgrid(xrange,yrange,zrange);

figure;
hcone = coneplot(x,y,z,u,v,w,cx,cy,cz,5);

fig2plotly(gcf, 'TreatAs', 'coneplot');


# Seting cone colors

load wind;

xmin = min(x(:));
xmax = max(x(:));
ymin = min(y(:));
ymax = max(y(:));
zmin = min(z(:));

xrange = linspace(xmin,xmax,8);
yrange = linspace(ymin,ymax,8);
zrange = 3:4:15;
[cx,cy,cz] = meshgrid(xrange,yrange,zrange);

figure;
hcone = coneplot(x,y,z,u,v,w,cx,cy,cz,5);

hcone.FaceColor = 'red';
hcone.EdgeColor = 'none';

fig2plotly(gcf, 'TreatAs', 'coneplot');


# Add vector field to background

Calculate the magnitude of the vector field (which represents wind speed sqrt(u.^2 + v.^2 + w.^2)) to generate scalar data for the slice command.

Create slice planes along the x-axis at xmin and xmax, along the y-axis at ymax, and along the z-axis at zmin. Specify interpolated face color so the slice coloring indicates wind speed, and do not draw edges.

load wind;

xmin = min(x(:));
xmax = max(x(:));
ymin = min(y(:));
ymax = max(y(:));
zmin = min(z(:));

xrange = linspace(xmin,xmax,8);
yrange = linspace(ymin,ymax,8);
zrange = 3:4:15;
[cx,cy,cz] = meshgrid(xrange,yrange,zrange);

figure;
hcone = coneplot(x,y,z,u,v,w,cx,cy,cz,5);

hcone.FaceColor = 'red';
hcone.EdgeColor = 'none';

hold on;
wind_speed = sqrt(u.^2 + v.^2 + w.^2);

hsurfaces = slice(x,y,z,wind_speed,[xmin,xmax],ymax,zmin);
set(hsurfaces,'FaceColor','interp','EdgeColor','none');
hold off;

fig2plotly(gcf, 'TreatAs', 'coneplot');

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Add a light source to the right of the camera and use Gouraud lighting to give the cones and slice planes a smooth, three-dimensional appearance.

load wind;

xmin = min(x(:));
xmax = max(x(:));
ymin = min(y(:));
ymax = max(y(:));
zmin = min(z(:));

xrange = linspace(xmin,xmax,8);
yrange = linspace(ymin,ymax,8);
zrange = 3:4:15;
[cx,cy,cz] = meshgrid(xrange,yrange,zrange);

figure;
hcone = coneplot(x,y,z,u,v,w,cx,cy,cz,5);

hcone.FaceColor = 'red';
hcone.EdgeColor = 'none';

hold on;
wind_speed = sqrt(u.^2 + v.^2 + w.^2);

hsurfaces = slice(x,y,z,wind_speed,[xmin,xmax],ymax,zmin);
set(hsurfaces,'FaceColor','interp','EdgeColor','none');
hold off;

camlight right;
lighting gouraud;
set(hsurfaces,'AmbientStrength',0.6);
hcone.DiffuseStrength = 0.8;

fig2plotly(gcf, 'TreatAs', 'coneplot');

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# Change the plot aspect ratio and the initial view angle

Changing aspect ratio of the plot can be done with daspect([2,2,1]).

Changing initial view angle is done with view(30,40).

load wind;

xmin = min(x(:));
xmax = max(x(:));
ymin = min(y(:));
ymax = max(y(:));
zmin = min(z(:));

xrange = linspace(xmin,xmax,8);
yrange = linspace(ymin,ymax,8);
zrange = 3:4:15;
[cx,cy,cz] = meshgrid(xrange,yrange,zrange);

figure;
hcone = coneplot(x,y,z,u,v,w,cx,cy,cz,5);

hcone.FaceColor = 'red';
hcone.EdgeColor = 'none';

hold on;
wind_speed = sqrt(u.^2 + v.^2 + w.^2);

hsurfaces = slice(x,y,z,wind_speed,[xmin,xmax],ymax,zmin);
set(hsurfaces,'FaceColor','interp','EdgeColor','none');
hold off;

camlight right;
lighting gouraud;
set(hsurfaces,'AmbientStrength',0.6);
hcone.DiffuseStrength = 0.8;

view(30,40)
daspect([2,2,1])

fig2plotly(gcf, 'TreatAs', 'coneplot');

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