******************************************************************************

 Analyse program "rdgpop" (Read grid populations)
 Purpose : Analyses the grid population read from file gridpop.
 Usage   : rdgpop [-f -i -last -g -a -s -o -t -n -w -ver -h -?] [nz  dof].

 Options : 
 -f FILE : the grid populations (densities) are read from file FILE
           rather than from ./gridpop
           The string FILE may be a relative or full path-name.
 -i FILE : Same as -f FILE
 -o FILE : The grid populations are written to file FILE.pl
           rather than to ./gpop.pl
           The string FILE may be a relative or full path-name.
           If FILE=no, i.e."-o no", no gpop.pl file will be opened.
 -last   : Write only the grid populations at final time to screen.
           The options -t, -skip, -cut are  ignored
           and nz=dof=0 is set, when this option is given.
 -t dt   : Print the maximal occupations every dt fs.
 -skip n : Skip the first n WFs when computing the 
           maximum over time of the grid populations.
 -cut n  : Consider only the first n WFs when computing the
           maximum over time of the grid populations
 -n      : No units. To be used when 'time-not-fs' is set.
 -g      : GNUplot command lines are written to the plot file.
 -a      : GNUplot is called automatically. (sets -g and -w).
 -s      : Grid populations for different states written separately to plot file.
 -w      : An existing property file is overwritten.
 -ver    : Version information about the program 
 -h      : Print this help text. 
 -?      : Print this help text. 

 There are two arguments: 
 The first argument is nz, i.e. the number of grid points sumed over.
 The second argument is dof, i.e. the runing number of the degree 
 of freedom to be considered. (dof=0 -> no output to file gpop.pl).
 If not enough arguments are given, the user is prompted for the
 missing arguments.
------------------------------------------------------------------------------