PU - Pen up ; PD - Pen down ; PA - Plot absolute - Page 360

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.