GAW data model

DATASET

Central object for data storage is dataset.c dataset.h.
User datas come, in general, as a form of a set of n variables, each variable
carryng m rows of datas. The first one should be the independant variable
and the other the dependant varaibles.
A variable may have more than one column.
A variable is stored in a structure WaveVar. Each pointer to WaveVar is stored
in a GPtrArray hold by dataset itself.
Gaw stores each column in a auto growing Glib GArray. The size of each entry
in Garray is size of double. 
Each pointer to GArray is stored in a GPtrArray hold by dataset itself.

GArray and and GPtrArray are Glib objects. They are auto growing, so rhe
developper don't need to take care of the size of data. The only constraint is
variable and data must feed in from column 0 to column n and so from row 0 to
row m. 

Accessing the data in done with the function dataset_val_get()
double dataset_val_get(WDataSet *wds, int row, int col )
{
   GArray *ary = g_ptr_array_index( wds->datas, col );
   
   double *val = &g_array_index (ary, double, row );
   return *val;
}


WAVETABLE
User data can have more than one dataset . so these datasets are stored in a 
GPtrArray hold by WaveTable.

SPICESTREAM
spicestream and its helper functions is an object to read data from file
and store them in dataset. The input file may have different formats.

SNDSTREAM
sndstream is analog to spicestream but handle the sound card.