------------------------------------------------------------------------------
 Purpose: To plot time-resolved photo-electron spectra.
 Usage  : tdpespec [-T|-S|-I|-P|-Ma] [-f -i -o -a -g -p -x -y -fac -n -no
                   -t -nofs -l -sm -w -nw -G -inter -ver -h -?] [name].

Output Formats : 
 -S      : "Step through" by pressing RETURN. (default).
 -M      : "Movie", one picture every second.
 -I id   : "Index file", id=0 shows the first picture, id=1 the second, etc.
 -P pnt  : "Point file", shows the population of the pnt-th grid-point over time.
 -T      : "3D time file" (grid file).
 -inter  : Opens interactive plotting menu.

Options  : 
 -f FILE : The wavefunction is read from file FILE rather than from ./gridpop
           The string FILE may be a relative or a full path-name.
 -i DIR  : Use DIR as name-directory.
 -o FILE : The output is written to file FILE_f* rather than
           to ./den1d_f*
           The string FILE may be a relative or a full path-name.
           If FILE=no, i.e. "-o no", no output file will be opened.
 -g      : GNUplot comand lines are written to the output file(s).
 -a      : GNUplot is called automatically. (sets -g and -w).
 -p      : Print GNUplot (sets -g). Allowed only with -I or -T.
 -sm     : Smooth the plot-data by splines. (Only for GNUplot, sets -g).
 -l      : Use logarithmic scale. (Only for GNUplot).
 -n step : Show only every step-th picture. (Only useful for -S, -M).
 -t tfinal : Show densities only up to t=tfinal.
 -no     : No output file opened.
 -nofs   : No transformation to fs. Use when 'time-not-fs' was set in mctdh.
 -x xmin xmax : Set the abszisse length (default: auto). Ignored for -T, -Ma.
 -y ymax : Set the ordinate length (default: auto). Ignored for -T, -Ma.
 -fac factor : Multiply the density values by factor.
 -G      : Plot gridlines.
 -w      : An existing output file is overwritten.
 -h      : Print this help text. 
 -?      : Print this help text. 
 -ver    : Version information about the program 

 The argument "name" gives the filestem for the directories with data.
 "name contains a pump-only calculation and "name_T" contain data 
 with a probe at varying times T. At least one T file is needed as 
 well as the pump only.
 If no argument is given, the user is prompted for the missing argument.
------------------------------------------------------------------------------