Algorithm 1.

OD matrix estimation from CDR data.

INPUT:	Call log database, the constants $\Delta T$, and $L_{min}$, and table of distances between geographic units$T_{min}{T}_{mmax}$
OUTPUT:	OD Matrix
01	Begin
02	$OD$ = NULL
03	For each day of the database
04	For each trip detected by two successive records of the same user, with distance $l_{ij}$ and in the time interval $\Delta T$
05	If$l_{ij}>L_{min}$ and $T_{min}\le \Delta T\le T_{max}$
06	Identify presumed domicile $i$
07	Compute de expansion factor $k_i$
08	$O{D}_{ij}\leftarrow O{D}_{ij}$ + $k_i$
09	End If
10	End For
11	End For
12	Returns $OD$ Matrix
13	End