clc;  clear;  hold on;
axis([-100,100,-100,100]);
plot(-100:100,0,'r.');
plot(0,-100:100,'r.');
x1=input('X1= ');
y1=input('Y1= ');
x2=input('X2= ');
y2=input('Y2= ');
dx=x2-x1;
dy=y2-y1;
if abs(dy)>abs(dx)
    length=abs(dy);
else
 length=abs(dx);
end
xinc=dx/length;
yinc= dy/length;
x=x1:xinc:x2;
y=y1:yinc:y2;
round(x)
round(y)
plot(x,y,'b.');
disp('X=')
disp(x')
disp('Y=')
disp(y')