How to plot values with different color with "if statement"

Hello,

I have a question. I have an .xlsx file with 3 columns. After that, I am making calculation between two first values. I would like to plot values x,y, depending on the value of the 3rd column (for example I would like to plot blue circle if 3rd column has 0 value and if 3rd column has 1 value I would like to plot red cirlce).

Could anyone help me?

Answer 1

[J. Alex Lee]

look at the documentation for the "scatter()" command. can you do what you want with that?

[Ivan Mich]

Excuse me , but I don;t understand you. Could you be more specific?

I want my x-y plot colors to depend on the value of the third column.

For example , for value 1 of the third column the color of the x y plot to be red.

for value 2 of the third column the color of the x y plot to be blue.

for value 0 of the third column the color of the x y plot to be green.

That's what I mean

[J. Alex Lee]

did you read the documentation for scatter()?

If you don't have stats toolbox for Ameer's answer, you can achieve the same thing with scatter()

x = [0.5 0.2 0;
     0.2 0.3 1;
     0.6 0.2 0;
     0.9 0.6 0;
     0.2 0.4 0;
     0.4 0.8 1;
     0.7 0.9 1;
     0.1 0.2 0];
 
colors = [1 0 0;  % red for 0s
          0 0 1]; % blue for 1s
      
scatter(x(:,1), x(:,2),[],x(:,3))
colormap(colors)

Answer 2

[Ameer Hamza]

Look at gscatter function(): https://www.mathworks.com/help/releases/R2020a/stats/gscatter.html. For example

x = [0.5 0.2 0;
     0.2 0.3 1;
     0.6 0.2 0;
     0.9 0.6 0;
     0.2 0.4 0;
     0.4 0.8 1;
     0.7 0.9 1;
     0.1 0.2 0];
 
colors = [1 0 0;  % red for 0s
          0 0 1]; % blue for 1s
gscatter(x(:,1), x(:,2), x(:,3), colors)