option nolet
ask pixels z1,z2
print "----------------------------------------------------------"
print " graph pixel   : part 1 ,                    version 1.0  "
print " peter.vlasschaert@gmail.com,09/02/2019                   "
print "----------------------------------------------------------"
print " max pixels x-direction (z1) = "; z1
print " max pixels y-direction (z2) = "; z2
print
print "---------------------------------------------------"
print " observe screen : from the front view of the screen"
print "---------------------------------------------------"
print " below= keyboard "
print " above= camera   "
print
print " draw a line : (x_mid,y_mid) to (x_mid+50,y_mid+50) "
x_mid = z1/2
y_mid = z2/2
x_1 = x_mid +50
y_1 = y_mid +50
set window 0,z1-1,0,z2-1
print
set color "red"
print "set window 0,z1-1,0,z2-1, color = red "
print " origin : below left bottom"
plot lines: x_mid,y_mid;x_1,y_1
set window 0,z1-1,z2-1,0
set color "blue"
print
print "-----------------------------------------"
print " used : book , A world tour of true Basic"
print " by : John R.Arscott                     "
print "-----------------------------------------"
print
print "set window 0,z1-1,z2-1,0, color = blue "
print " origin : above left top "
plot lines: x_mid,y_mid;x_1,y_1
end