How do I get graph colors to show as defined?

I have a table with a variable (my_table.my_config) that holds the configuration names of a component. I added a variable to my table to contain a unique color for each configuration. The configuration variable is categorical, hence the following code:

my_table.my_colors = my_table.my_config;   %copy the configuration categorical, then change to define corresponding colors
my_table.my_colors = renamecats(my_table.mb_colors, {'red', 'green', 'blue', 'black'});

The swarm chart is

figure;
y = swarmchart( my_table.xvar, my_table.yvar, 10, my_table.my_color, 'filled');

The colors are not red, green, blue, and black. Any idea why not?

categories(my_table.my_colors)

ans =

  4×1 cell array

    {'red'  }
    {'green'}
    {'blue' }
    {'black'}

[Ted H]

Note:

I ran the code in the accepted answer of this thread and got the expected colors.

I followed the example in the section titled Display Filled Markers with Varied Color in the matlab documentation for swarmchart.

[Ted H]

I think I figured it out.

I revised and added as follows:

my_table.my_colors = my_table.my_config;   %copy the configuration categorical, then change to define corresponding colors
my_table.my_colors = renamecats(my_table.mb_colors, {'1', '2', '3', '4'});
my_table.my_colors = double(my_table.my_colors);
map = [0 0 1
        0 1 0
        1 0 0
        0 0 0];

and the swarmchart becomes

figure;
colormap(map);
y = swarmchart( my_table.xvar, my_table.yvar, 10, my_table.my_color, 'filled');

Answer 1

[Cris LaPierre]

The issue is that color name can only be used to specify a single color for all data points. If you want to specify a different color for each point, you must use a numeric value

• RGB triplet
• matrix of RGB triplets
• vector of colormap indices

(see the table here).

If you are particular about the color used, then I suggest predefining the colors, and using group numbers to select the appropriate color. Here's a simple example

my_table = table(randi(2,100,1),randn(100,1),'VariableNames',["xvar","yvar"]);
my_table.my_config = discretize(my_table.yvar,4);
% define colors
colors = [1 0 0; 0 1 0; 0 0 1; 0 0 0];
% use group number from my_config to select rgb triplet 
my_table.my_colors = colors(my_table.my_config,:)

my_table = 100×4 table
    xvar      yvar      my_config     my_colors 
    ____    ________    _________    ___________

     2        0.1512        3        0    0    1
     2      -0.43599        3        0    0    1
     2        1.1765        4        0    0    0
     2       0.34772        3        0    0    1
     1      -0.26273        3        0    0    1
     2      -0.40591        3        0    0    1
     2       0.19128        3        0    0    1
     2      -0.10313        3        0    0    1
     2        1.3358        4        0    0    0
     1       0.35625        3        0    0    1
     1        0.8239        4        0    0    0
     1      -0.98383        2        0    1    0
     1       -1.1343        2        0    1    0
     2       0.37888        3        0    0    1
     1      -0.22596        3        0    0    1
     2        1.6522        4        0    0    0

s = swarmchart(my_table,'xvar','yvar','filled','ColorVariable','my_colors','SizeData',50);

[Ted H]

Thanks @Cris LaPierre for the clarification. My final code is as follows:

measures = ["yvar1", "yvar2", "yvar3", "yvar4"]; % my table has several more yvar's
idx = rand(100,1)>.3;
for i = 1 : numel(measures)
    figure;
    colormap(map);
    y = swarmchart( my_table(idx,:), 'xvar', (measures(i)),'filled', 'ColorVariable','mb_colors');
    set(gca,'color',[0.95 0.95 0.95]);
    y.SizeData = 10;
    title( measure_labels(i) );
    ylabel( measure_units(i) );

(different topic than original post) I had to define the SizeData on a seperate line because matlab was throwing 'Invalid parameter/value pair arguments' errors, and I could not find what pair to use. The examples are simple graphs, and I am not able to pull it together from those.

from my dataset: (this is the expected graph)

[Cris LaPierre]

You can incorporate SizeData using 'SizeData' name-value pair.

swarmchart( my_table(idx,:), 'xvar', (measures(i)),'filled', 'ColorVariable','mb_colors','SizeData',10);

[Ted H]

Can you confirm if the SizeData pair cannot be before the 'filled' entry? I thought I tried that pair, and it bombed.

[Cris LaPierre]

You are using the table syntax, so you must follow that convention:

• swarmchart(tbl,xvar,yvar,'filled')

swarmchart(mytable,"xvar","yvar",'filled',...)

If you want to use the array syntax, you would have to extract vectors from the table.

• swarmchart(x,y,sz,c)

swarmchart(mytable.x,mytable.y,size,mytable.my_color)