GRAPH_DATE — Function to add date values in abscissae of time series graphs
[ok]=GRAPH_DATE(f,TS)
Number of the figure to modify (axes handle obtained with gca() function)
Time step increment of abscissae. Must take values of the form [Nb of TS].[TS name] with [TS name]= "y","m","d". ex: 3.m -> 3 months ticked graph
The function plots the time series on small graphs and save them under a gif file format.