15.34  CLEAR 

{CLEAR|ERASE} [FROM] [x,y[,z]|CURSOR] [DATA] TO[x,y[,z]|CURSOR] [DATA]
This  clears  the  screen  without  resetting  the  buffers or the default
values.  This is useful if you wish to view several different things  with
the same parameters.  If you specify a pair of X,Y values only a rectangle
inside those values is cleared.  This only works on terminals that support
selective  erase.   Each  X,Y[,Z]  may be specified in either Text or Data
coordinates.  Text coordinates are assumed if a Z is not specified.


                                  WARNING

     After  CLEAR  the  current  scale  settings  are  retained,  and
     subsequent plots will not automatically have axes or scales.  In
     general you should use command NEW.