How do I make my circle display in pink and background in white color?

This is my code at the moment. I'm trying to generate a circle in a 500x500 pixel spectrum with a fixed radius. I want to export all the circles created as images. I don't know how to make my circle display in pink or the background to be in white.

%parameteres
shape = [500 500]; % [y x]
shapecolor = [1 0.3 0.5];
backgroundcolor = [100 100 100];

% set up some things
numimges = 1;
archive = 'circulorosa';
nameofdatabase = 'cuadrado';


for k = 1:numberimages

radius = 5; 
center =  (shape-2*r-1).*rand(1,2)+1+r; % (y,x);
viscircles(center,r,'Color','b');
axis square;

end 

Unrecognized function or variable 'numberimages'.

Answer 1

[KSSV]

[m,n] = deal(500) ;   % side of image 
I = ones(m,n,3) ;   % initialize image with white background 
% GEt cirlce on the image 
[X,Y] = meshgrid(1:n,1:m) ; 
C = [mean(X(:)) mean(Y(:))] ;
th = linspace(0,2*pi)' ; 
R = 5 ; 
x = C(1)+R*cos(th) ;
y = C(2)+R*sin(th) ; 
idx = knnsearch([X(:) Y(:)],[x y]) ;
% Give pink color to circle pixels on image 
c = [255,192,203]/255;  % pick RGB color ocde 
for i = 1:3
    T = I(:,:,i) ; 
    T(idx) = c(i) ; 
    I(:,:,i) = T ; 
end
imshow(I)

[marsmar]

How could I color the inside of pink also? What would happen if I'm looking for a specific shade of pink too?

[KSSV]

Just replace, knnsearch with inpolygon.

[m,n] = deal(500) ; 
I = ones(m,n,3) ; 
[X,Y] = meshgrid(1:n,1:m) ; 
C = [mean(X(:)) mean(Y(:))] ;
th = linspace(0,2*pi)' ; 
R = 5 ; 
x = C(1)+R*cos(th) ;
y = C(2)+R*sin(th) ; 

idx = inpolygon(X, Y,x,y) ;
c = [255,192,203]/255;
for i = 1:3
    T = I(:,:,i) ; 
    T(idx) = c(i) ; 
    I(:,:,i) = T ; 
end
imshow(I)

To have your required shade, just replace the variable c (it is RGB color code) to your desirable.

[KSSV]

[m,n] = deal(500) ;

[X,Y] = meshgrid(1:n,1:m) ;
th = linspace(0,2*pi)' ;
R = 50 ;
c = [255,192,203]/255;
for i = 1:9
    % generate random centers for circle 
    C = [randsample(1:n,1),randsample(1:m,1)] ;
    
    x = C(1)+R*cos(th) ;
    y = C(2)+R*sin(th) ;
    
    idx = inpolygon(X, Y,x,y) ;
    
    I = ones(m,n,3) ;
    for j = 1:3
        T = I(:,:,j) ;
        T(idx) = c(j) ;
        I(:,:,j) = T ;
    end
    subplot(3,3,i)
    imshow(I)
end

[marsmar]

Thank you! If i wanted to change the angle or the central postion where the circle is at? How could I do that? Or what functions?

[KSSV]

Check C, this is the cneter of circle.

Answer 2

[Image Analyst]

You never assigned numberimages, only numimges which is spelled differently. Try

numberimages = 20; % Or whatever you want.