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Matlab How to make 2D plot of points with different colors?

  1. Dec 13, 2016 #1


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    I want to make a 2D plot of points with different x, y coordinates and have colors depending on a separate variable. I have make column vectors for x and y coordinates and another column containing 1 or -1. I would like to represent the points with 1 as red and -1 as blue points. I have codes as follow:
    Code (Matlab M):

    x_dis=rho_rec(1:nDis,xCol,step);%x coordinates
    y_dis=rho_rec(1:nDis,yCol,step); %y coordinates
    bv=rho_rec(1:nDis,bvCol,step); % 1 or -1

    for i=1:1:nDis
       if bv(i)==1
            dis_color(i,1:3)=[0 0 1]; %blue
        elseif bv(i)==-1
            dis_color(i,1:3)=[1 0 0]; %red


    However it doesn't work. How should I modify the code? Thank you.
    Last edited by a moderator: Dec 13, 2016
  2. jcsd
  3. Dec 13, 2016 #2


    Staff: Mentor

  4. Dec 13, 2016 #3


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    Gold Member

    I have changed to use scatter instead of plot, as suggested by other
    So the command becomes:


    It works like a charm
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