PICK:automatic_digitizing

1_example

 Suppose you have entered:    GRAPH X1 Y1
                              GRAPH\NOAXES X2 Y2
                              GRAPH\NOAXES X3 Y3
 Then to pick points off the three curves: PICK XP YP YP1 YP2 YP3 
 and move the crosshair horizontally across the screen and type the
 R key at each location you desire a value.  The vector YP1 will
 contain the interpolated values from curve (X1,Y1), YP2 will contain
 those from (X2,Y2), and YP3 will contain those from (X3,Y3). The
 horizontal (independent) coordinates will be contained in XP.

2_example

 Suppose you have entered:    GRAPH X1 Y1
                              GRAPH\NOAXES X2 Y2
                              GRAPH\NOAXES X3 Y3
 To pick points off of the third curve drawn:  PICK XP YP YP3 3
 and move the crosshairs horizontally across the screen and type
 the R key at the locations where you desire values off the third
 curve. The vector YP3 will contain the interpolated values from
 curve (X3,Y3), while the horizontal (independent) coordinates will
 be contained in vector XP.