CHAPTER 9 HP-GL - 8 
IW - Input window  
IW [ X
1
, Y
1
, X
2
, Y
2
 ] [;] 
X1-Window lower left X coordinate     Y1-Window lower left Y coordinate 
X2-Window upper right X coordinate     Y2-Window upper right Y coordinate 
 
  This instruction sets the window inside which plotting can be performed. 
  Graphic units are always used. 
  Coordinate values for X1, Y1, X2 and Y2 are integer numbers from 0 to 32,767. 
  The order of the pairs (X1, Y1) and (X2, Y2) may be reversed with no change in the window created:  "IW 
X1, Y1, X2, Y2" is identical in effect to "IW X2, Y2, X1, Y1". 
  Using this instruction without a parameter field releases any previous limitations on the plot area. 
 
(X2,Y2)
(X1,Y1)
Window
Print paper
 
 
RO - Rotate coordinate system  
RO [q][;] 
q : Angle in degrees through which the coordinate system is rotated. 
 
  This instruction rotates the coordinate system. 
  A value of 0 or 90 must be used for q. 
  Using this instruction without a parameter field sets the rotation of the coordinate system to 0 degrees. 
 
PG - Page feed 
PG [;] 
  Executes a page feed 
  After page feeding,  the cursor position return to the home position (0, 0). 
 
3.3.  Pen Control and Plot Instructions 
Instruction Function 
PU Pen Up 
PD Pen Down 
PA Plot Absolute 
PR  Relative Coordinate Pen Move 
AA  Absolute Arc Plot 
AR  Relative Arc Plot 
CI Circle