MATLAB: Problem with scatter/bubble plot

Question

hi,

i have created a vector containing coordinates of a circle in a matrix.

i want to display these locations as dots in a plot.further i want to color these dots in a clockwise increasing color scheme. i have written a code but experienced a problem : the color vector which i created does not seem to be mapped linearly to my location points

code:

   matrix = ones(512,512); 
   mittelpunkt_x = 256; 
   mittelpunkt_y = 256; 
   radius = 33; 
for i=1:size(matrix,1) 
     for j = 1:size(matrix,2) 
         matrix(i,j) = norm([i j]-[mittelpunkt_x,mittelpunkt_y],2); 
          if matrix(i,j)<=radius 
          matrix(i,j)=0;%10; 
           elseif matrix(i,j)<radius+1 && matrix(i,j)>radius 
          matrix(i,j)=1; 
         else 
             matrix(i,j)=0; 
         end 
       end 
  end 
b=0.00490196078
[r,c]=find(matrix==1);
color=[b:b:1]; 
y=[r c]; 
scatter(r,c,50,color,'filled')

i hope someone can help me with this

g3rm9

Answer 1

something like this?

t = 0:pi/6:2*pi
t(13)=[];
x = cos(t);
y = sin(t);
c = spring(12);
scatter(x,y,[],c,'filled')