I am not sure what you mean when you say "there is no graph used", but maybe something like the exa,ple below might help.
clear,clc
x0 = [20 150]; % x coordinates of source and destination
y0 = [30 100]; % y coordinates of source and destination
slope = diff(y0)/diff(x0);
x = linspace(20,150,500);
y = slope*(x-x0(1))+y0(1);
figure(1)
for i = 1:length(x)
plot(x(i),y(i),'ok','MarkerFaceColor','r')
axis([10 160 20 110])
drawnow
end
