Different colors for a gscatter plot (RGB triplets)

Hi all,

I'm a beginner in Matlab and I have an issue with the gscatter function.

I need to do a figure similar to that one, but i would like to use different colors, defined by the RGB triplet (for instance [0.5 0.1 0.8])

Here a part of the code. It works, but I can't use the RGB triplet, but only the standard colores defined by rgby.....any suggestion? I would need to use seven different RGB triplets. Thank you

col='rgbymck'
g= gscatter(x,y,order,col,'o');

for n = 1:length(g)
  set(g(n), 'MarkerFaceColor', col(n));
end
for n = 1:length(g)
  set(g(n), 'MarkerEdgeColor', 'k');
end
xlim([30 70])..


hold on

m= gscatter(x2, y2, order2,col,'^');

for n = 1:length(m)
  set(m(n), 'MarkerFaceColor', col(n));
end
for n = 1:length(m)
  set(m(n), 'MarkerEdgeColor', 'k');
end
xlim([30 70])

Answer 1

[Stephan]

Hi,

RGB triplets can be used - see here. Therefore activate the filled option.

Best regards

Stephan

[Alberto Caracciolo]

Yes I know i could use RGB triplets but I don't understand how to set up the code.

I've tried with something like that but i doesn't work!

col= '[0.4 0.4 0.4] [0.2 0.2 0.2]'

[Stephan]

col= '[0.4 0.4 0.4] [0.2 0.2 0.2]'

reutrns a char - this is not suitable for your purposes. Use a cell array instead:

col= {[0.4 0.4 0.4] [0.2 0.2 0.2]}

>> col{1}

ans =

    0.4000    0.4000    0.4000
    
>> col{2}

ans =

    0.2000    0.2000    0.2000

See this example:

x = 1:10;
y(1,:) = randi(10,1,10);
y(2,:) = randi(15,1,10);
y(3,:) = randi(5,1,10);

col = {[0.4 1 0.4] [1 0.2 0.2] [0.5 0.6 1]}

hold on
for k = 1:3
    scatter(x,y(k,:),'MarkerEdgeColor',col{k} ,'MarkerFaceColor',col{k})
end

[Alberto Caracciolo]

I see. now i have

col=[0.4 0.4 0.8;0.5 0.5 0.8;0.1 0.7 0.8;0.3 0.5 0.7;0.8 0.6 0.1;0.4 0.5 0.2;0.1 0.1 0.1]

and

m= gscatter(x2, y2, order2,col,'^');

for n = 1:length(m)
  set(m(n), 'MarkerFaceColor', col(n));
end
for n = 1:length(m)
  set(m(n), 'MarkerEdgeColor', 'k');
end
xlim([30 70])

but i get a different error:

Error using matlab.graphics.chart.primitive.Line/set

Error setting property 'MarkerFaceColor' of class 'Line':

Color value must be a 3 element vector

thank you

[Stephan]

try:

col(n,:))

To understand whats going on read about linear indexing and check this:

>> col=[0.4 0.4 0.8;0.5 0.5 0.8;0.1 0.7 0.8;0.3 0.5 0.7;0.8 0.6 0.1;0.4 0.5 0.2;0.1 0.1 0.1]

col =

    0.4000    0.4000    0.8000
    0.5000    0.5000    0.8000
    0.1000    0.7000    0.8000
    0.3000    0.5000    0.7000
    0.8000    0.6000    0.1000
    0.4000    0.5000    0.2000
    0.1000    0.1000    0.1000

>> n = 2

n =

     2

>> col(n)

ans =

    0.5000

>> col(n,:)

ans =

    0.5000    0.5000    0.8000

[Alberto Caracciolo]

Thank you it works! :)