Version 12 (modified by 12 years ago) ( diff ) | ,
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Transition probability matrix generation:
- convert timestamp to serial number and then sort
- divide area into grids
- loop: for each taxiid, find current grid & next grid, fill into grid matrix (row is current grid #, column is next grid #)
- get probability matrix by normalizing grid matrix
Update generation:
- set parameters, such as the number of updates, grid number, longitude and latitude range
- choose GUID/TAXIID randomly
- find GUID/TAXIID's current location (longitude and latitude) and convert it to AS/gird number
- compute destination AS/grid number through transition probability matrix (convert to probability CDF matrix)
- find timestamp
table TAXIDATA has all data loaded, table TAXI1 loads only the first data file
table contents are as below
CREATE TABLE TAXIDATA
(
ID NUMBER(10) CONSTRAINT TAXIDATA_ID NOT NULL,
TAXIID NUMBER(7),
LONGITUDE NUMBER(9,6),
LATITUDE NUMBER(8,6),
SPEED NUMBER(3),
ANGLE NUMBER(3),
DATETIME TIMESTAMP(6),
STATUS NUMBER(1),
EXTENDSTATUS NUMBER(1),
REVISED NUMBER(1),
PRIMARY KEY(ID) )
TABLESPACE USERS;
The picture shows 10k entries chosen from the first data file. The covered area is longitude from 121.2 to 121.8 and latitude from 31 to 31.5. The area is divided into 10*10 grids, which is 100 grids in total.
Attachments (1)
-
location(10K_100grids).jpg
(115.9 KB
) - added by 12 years ago.
show locations in most condense area which is divided into 100 grids
Download all attachments as: .zip