You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: trainseg.m
    path of file: ./repos/machinevision-toolbox-matlab
    
    the code of the file until where you have to start completion: %TRAINSEG	Interactively train a color segmentation
%
%	map = trains
    
function map = colorseg(im)

	% convert image to (r,g) coordinates
	y = sum(im, 3);
	r = round( im(:,:,1) ./ y * 255);
	g = round( im(:,:,2) ./ y * 255);

	% display the original image

	% create and display the map
	map = zeros(256, 256);
	hm = figure
	set(gcf, 'Units', 'normalized', 'Position', [0.1 0.5 0.8 0.4])
	subplot(121)
	image(im)
	axis('equal')
	title('input image')

	subplot(122)
	image(map)
	axis('equal')
	xlabel('r');
	ylabel('g');
	colormap(gray(2));
	title('segmentation map')

	while 1,
		subplot(121)
		[y,x] = ginput(1);
		if isempty(y),
			break;
		end