CHAPTER 9 HP-GL - 9 
PU - Pen up  
PU [ X,Y [,...]] [;] 
X ; X coordinate of the cursor movement destination 
Y ; Y coordinate of the cursor movement destination 
 
  X and Y are either relative or absolute, depending on whether a PA or a PR was the last plot command 
executed.  The absolute coordinates are set as default. 
  Moves the cursor to the specified coordinates after raising the pen. 
  Using this instruction without a parameter field  raises the pen without changing the cursor position. 
  When scaling is on, user coordinates are used. 
  Also, when scaling has been performed, the values for X and Y are real numbers. 
  When scaling is off graphics units are used. 
  When there is no scaling, the coordinates values for X and Y are integer numbers. 
 
Current position
(X1, Y1)
(X2,Y2)
(X3, Y3)
(Xn, Yn)
 
 
PD - Pen down 
PD [ X, Y [,...]] [;] 
X ; X coordinate of the cursor movement destination 
Y ; Y coordinate of the cursor movement destination 
 
  X and Y are either relative or absolute, depending on whether a PA or a PR was the last plot command 
executed.  The absolute coordinates are set as default. 
  Moves the cursor to the specified coordinates after lowering the pen.  (This plots a straight line.) 
  Using this instruction without a parameter lowers the pen without changing the cursor position.  ( One dot is 
plotted.) 
  When scaling has been performed,  the cursor is moved by user coordinates. 
  Also, when scaling has been performed, the values for X and Y are real numbers. 
  When there is no scaling,  the cursor is moved by absolute coordinates in graphics units. 
  When there is no scaling, the coordinate values for X and Y are integer numbers. 
 
Current position
(X1, Y1)
(X2,Y2)
(X3, Y3)
(Xn, Yn)
 
 
PA - Plot absolute 
PA [X, Y [,...]] [;] 
X ; X coordinate of the cursor movement destination 
Y ; Y coordinate of the cursor movement destination 
 
  X and Y are absolute values in user units or graphics units. 
  Moves the cursor to the specified coordinates. 
  Plots a straight line only when the pen is down. 
  When scaling has been performed,  the values for X and Y are integer numbers. 
  When there is no scaling,  the cursor is moved by absolute coordinates in graphics units. 
  When there is no scaling,  the coordinate values for X and Y are integer numbers.