creation of the frequencies data base
def_basets(basefqnum,basefqlit)
* basefqnum = a (nr x nc) matrix of frequencies
--> if nc == 1 then all frequencies are at most annual (monthly, quarterly, ... as well as annual)
--> if nc == 2 then frequencies can be less than annual; in that case each row has a 1 in the first or second cell
- a 1 in the first cell means that the frequency is less than annual (decades, centuries,...) and the second cell is the frequency (10 for decades, 100 for centuries,...)
- a 1 in the second cell means that the frequency is more than annual (monthly, quarterly, weekly, ... as well as annual) and the first cell is the frequency (12 for monthly, 4 for quarterly, ... 1 for annual)
* basefqlit = a string matrix associating a symbol to the daily and weekly ts, and then to each frequency in basefqnum
* nothing: data are saved into the file SCI\macros\grocer\db\basets.dat