How to create a 4D plot.

Hello friends,

I have three variables:

,

,

,

with condition .

. ,

and .

.

How to generate the graph for . ,

Answer 1

[Walter Roberson]

x = 0:.01:1;  y = x; z = x;
[X,Y,Z] = meshgrid(x,y,z);
mask = X.^2 + Y.^2 + Z.^2 <= 1;
F = sqrt(1-(X.^2+Y.^2+Z.^2));   %caution, need this order because of round-off

subplot(1,2,1)
scatter3(X(mask),Y(mask),Z(mask),20,F(mask));

subplot(1,2,2);
F2 = F;
F2(~mask) = nan;
for level = 0.2:0.2:0.8
    isosurface(X, Y, Z, F2, level);
end

[Rajkumar Verma]

Thanks for this code. I want another type of graph for this data. Please see the attached graph. Please help me to get this type of graph for this data.

[Walter Roberson]

That plot does not meet your original requirement to create a 4D plot of (x, y, z, f) . That plot is x, y, z with a single f value, and with two lights of different colors to provide the two different colors for inside and outside. (I am not certain at the moment where the two lights are positioned. The red one is plausibly at the origin, but the blue one is a bit of a puzzle.)

[Rajkumar Verma]

Ok. Thanks for your comment. How can I draw this graph with any colour?

[Walter Roberson]

isosurface(X, Y, Z, F2, level)

for level in the range 0 to 1 (representing the F value that you want to plot for.)

[Rajkumar Verma]

Thanks for your kind help.

[Gustavo Lunardon]

Hello!

How would you apply the scatter3 command to plot all the grid points if you had no inequality (no mask)?

Is there a more elegalnt solution than just selecting an inequality that would always be satisfied?

[Walter Roberson]

scatter3(X(:), Y(:), Z(:), 20, F(:));   %F will be used for color information