Modify the color of a scatter3 plot

I have the following command

scatter3(X,Y,Z,20,sector,'.')

The value 'sector' is responsile of the color. If I display it is like

sector = 1

1

1

...

2

2

2

...

3

3

3

But I would like to change the color associate to it in order to have a special red when sector is 1, a special blue for 2 and a special yellow when it's 3

How could I do

Answer 1

[dpb]

https://www.mathworks.com/matlabcentral/answers/233084-changing-color-of-the-points-in-scatter3?s_tid=answers_rc1-3_p3_MLT#answer_188811

Answer 2

[Yoan]

I find a solution with this

sector_str=[];
for i = 1 : length(sector)
    if sector(i) == 1
        sector_str(i,:) = [1 0 0];
    elseif sector(i) == 2
        sector_str(i,:) = [0 0 1] ;
    elseif sector(i) == 3
        sector_str(i,:) = [1 1 0] ;
    else
        sector_str(i) = 'k' ;
    end
end
scatter3(X,Y,Z,20,sector_str,'.')

[Steven Lord]

There's no need for a loop here. Let's make some sample data to show the technique.

sampleData = randi(4, 10, 1)

sampleData = 10×1

4 3 4 2 1 4 1 2 4 1

Here's the list of colors.

listOfColors = [1 0 0; 0 0 1; 1 1 0; 0 0 0]

listOfColors = 4×3

1 0 0 0 0 1 1 1 0 0 0 0

Now just use indexing to create the array of M-by-3 color data.

colors = listOfColors(sampleData, :)

colors = 10×3

0 0 0 1 1 0 0 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0

[dpb]

"The MATLAB way" -- use vector lookup...don't need explicit loops/case/if..

CLRS=[[1 0 0];[0 0 1];[1 1 0]];  % the lookup table
X=randi([1 10],10,1);Y=randi([1 10],10,1);Z=randi([1 10],10,1);
sector=randi([1 3], size(X));
scatter3(X,Y,Z,[],CLRS(sector,:),'filled','markerEdgeColor','k')

Answer 3

[Walter Roberson]

N = 10;
sector = randi(4, N, 1)

sector = 10×1

3 3 1 1 3 1 3 1 2 3

listOfColors = [1 0 0; 0 0 1; 1 1 0; 0 0 0]

listOfColors = 4×3

1 0 0 0 0 1 1 1 0 0 0 0

X=randi([1 10],N,1); Y=randi([1 10],N,1); Z=randi([1 10],N,1);
scatter3(X, Y, Z, [], sector);
colormap(listOfColors)