Spherical 3D array

Hi,

I am very new to matlab and I hope someone can help me. I am desperately trying to generate a 3D array in the shape of a sphere (instead of a 3D cuboid). I also want to set the value of each element of the 3D spherical array to 99 and plot it. Does anyone know how I should do it? I have tried with a cuboid as shown below:

T=12; N=24; row=1; for z=(((2*N-T)/4)+1): ((((2*N+T)/4))) for y=(((2*N-T)/4)+1): ((((2*N+T)/4))) for x=(((N-T)/2)+1): (((N+T)/2))

                        array(x,y,z) = 99;
                        array(row,1)=y;array(row,2)=x;array(row,3)=z;
                        row=row+1;
                    end
                end
            end
plot3(array(:,2), array(:,3), array(:,1),'r*', 'Color', [0, 0, 0])

I would very much appreciate if someone could help. thanks

Answer 1

[Walter Roberson]

MATLAB is not able to create numeric arrays in the shape of a sphere, only in N-dimensional cuboids.

You can create a cube and fill in the (discrete approximation to) a sphere within it, but then you run into difficulties in plotting the result. 3 spacial dimensions plus one value per location gives you 4 dimensional data, and there is no plotting routine for 4 dimensional data.

If I recall correctly there is a MATLAB File Exchange contribution that does some voxelization drawing.

Answer 2

[jerry brackett]

int a[10] [3] [5] its base address is 89. what is the address of element a[7] [2] [4] ?