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Preday System

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smart-fm edited this page Nov 9, 2018 · 1 revision

This page attempts to succinctly summarize the overall design and flow of information in the Preday System of SimMobility, include a summary of the functions thereof. (NOTE: this is still work in progress)

PredaySystem Functions:

  • predictUsualWorkLocation
  • predictTourMode
  • constructTourModeParams
  • predictTourModeDestination
  • predictTourTimeOfDay
  • predictSubTours
  • predictSubTourModeDestination:
  • predictSubTourTimeOfDay: predicts time period of subtour activity
  • constructIntermediateStops
  • generateIntermediateStops
  • predictStopModeDestination
  • predictStopTimeOfDay
  • fetchTravelTime
  • calculateArrivalTime
  • calculateDepartureTime
  • calculateTourStartTime
  • calculateTourEndTime
  • calculateSubTourTimeWindow
  • blockTravelTimeToSubTourLocation
  • constructTours
  • getRandomNodeInZone
  • getFirstNodeInZone

PredayManager Functions:

  • loadPersonIds:

    • calls the following populationDao methods: getIncomeCategories, getAddresses and getAllIds
    • the corresponds SPs must exist in the database for Persons to be loaded successfully

  • loadZones:

    • gets all parameters for zones from network database

  • loadZoneNodes

  • loadPostCodeNodeMapping

  • loadCosts

  • loadUnavailableODs: loads the unavailable origin destination pairs; e.g for private modes: const std::string DB_GET_PVT_UNAVAILABLE_OD = "SELECT "+ DB_FIELD_TCOST_ORIGIN + ", " + DB_FIELD_TCOST_DESTINATION + " FROM " + DB_TABLE_TCOST_PVT + " WHERE info_unavailable = TRUE";

  • dispatchLT_Persons:

    • Distributes long-term persons to different threads and starts the threads which process the persons
    • Also accounts for single-threaded case
    • Depending on what mode of preday is being run, one of these two functions are called: computeLogsumsForLT_Population (logsum mode) or processPersonsForLT_Population (simulation mode).

Currently, getAddresses executes the query in the SP synpop12.getaddresses_aditi():

CREATE OR REPLACE FUNCTION synpop12.getaddresses_aditi()
 RETURNS TABLE(address_id bigint, postcode integer, taz_code integer, distance_mrt double precision, distance_bus double precision)
 LANGUAGE plpgsql
AS $function$
BEGIN
    RETURN QUERY
    (
      SELECT synpop12.sla_addresses.address_id,
cast(synpop12.sla_addresses.sla_postcode as integer),
demand.postcode_node_map.node_zone,
synpop12.postcode_amenities.distance_mrt,
synpop12.postcode_amenities.distance_bus
        FROM synpop12.sla_addresses,demand.postcode_node_map,
synpop12.postcode_amenities
     WHERE synpop12.sla_addresses.address_id =
synpop12.postcode_amenities.address_id
AND synpop12.sla_addresses.sla_postcode not in ('000000','999999','881091')
AND synpop12.sla_addresses.sla_postcode::bigint = demand.postcode_node_map.postcode
    );
END;$function$

This SP returns the postcode ID, TAZ ID, MRT distance and Bus Distance for all address IDs for the population. Here is an excerpt of the first 10 lines of output from the SP (select synpop12.getaddresses_aditi() in psql):

getaddresses_aditi          
--------------------------------------
(1,0,23,1.65803739,0.986284272)
(2,1,17,1.688481697,0.176789371)
(3,2,17,4.155894104,2.496732718)
(4,3,18,3.448476969,0.935323782)
(5,4,24,0.462769223,0.44654096)
(6,5,7,0.867990472,0.590665825)
(7,6,21,2.460223466,0.696569724)
(8,7,20,1.72407327,1.432121356)
(9,8,19,3.726448416,1.868370401)
(10,9,20,3.569378391,2.09445594)

Below are snippets of the relevant tables.

demand.postcode_node_map table:

postcode | postcode_zone | node_id | node_zone | node_postcode_distance
----------+---------------+---------+-----------+------------------------
       0 |            23 |      51 |        23 |            99.57216822
       1 |            17 |      45 |        17 |            628.5636693
       2 |            17 |      90 |        17 |            176.5118655
       3 |            18 |      92 |        18 |            430.1252246
       4 |            24 |      62 |        24 |            167.7026194

The zones (TAZes) are subsets of the postcodes.

synpop12.sla_addresses table:

address_id | sla_postcode | taz_id |    x_coord    |    y_coord    | primary_postcode | status_0812
------------+--------------+--------+---------------+---------------+------------------+-------------
         1 | 0            |     23 | 366722.971678 |  138853.08784 | t                |           0
         2 | 1            |     17 |  370621.67408 | 139516.020701 | t                |           0
         3 | 2            |     17 | 374245.873626 | 139124.893613 | t                |           0
         4 | 3            |     18 | 373582.093849 | 142731.728244 | t                |           0
         5 | 4            |     24 | 370935.033375 | 143423.244607 | t                |           0
         6 | 5            |      7 | 367350.426553 |  143184.23181 | t                |           0
         7 | 6            |     21 | 367347.747512 | 146481.997364 | t                |           0
         8 | 7            |     20 | 370983.480189 | 146654.574143 | t                |           0

The synpop12.postcode_amenities table:

address_id | sla_postcode | taz_id | mrt_station | distance_mrt | distance_bus | distance_express | distance_pms30 | distance_cbd | distance_mall | mrt_200m | mrt_400m | express_200m | bus_200m | bus_400m | pms_1km
------------+--------------+--------+-------------+--------------+--------------+------------------+----------------+--------------+---------------+----------+----------+--------------+----------+----------+---------
         1 | 0            |     23 | SC1         |   1.65803739 |  0.986284272 |      0.099572168 |    1.057905068 |  2.717167614 |          1.14 | f        | f        | t            | f        | f        | f
         2 | 1            |     17 | NS1         |  1.688481697 |  0.176789371 |      0.176789371 |    1.058097214 |  3.423081497 |          1.14 | f        | f        | t            | t        | f        | f
         3 | 2            |     17 | SC3         |  4.155894104 |  2.496732718 |      0.176511866 |    2.021189467 |  6.878215466 |          1.14 | f        | f        | t            | f        | f        | f
         4 | 3            |     18 | NS5         |  3.448476969 |  0.935323782 |      0.935323782 |    1.978261409 |  7.041848217 |          1.14 | f        | f        | f            | f        | f        | f
         5 | 4            |     24 | NS4/SC4     |  0.462769223 |   0.44654096 |       0.16770262 |    0.388305031 |  3.793507219 |          1.14 | f        | f        | t            | f        | f        | t
         6 | 5            |      7 | SC5         |  0.867990472 |  0.590665825 |      0.135579131 |    0.317977943 |  1.855746838 |          1.14 | f        | f        | t            | f        | f        | t
         7 | 6            |     21 | SC5         |  2.460223466 |  0.696569724 |      0.438422587 |     0.57903861 |  5.126539234 |          1.14 | f        | f        | f            | f        | f        | t
         8 | 7            |     20 | NS5         |   1.72407327 |  1.432121356 |      0.314532891 |    1.790862456 |  6.197386616 |          1.14 | f        | f        | f            | f        | f        | f

It is important to note that in Virtual City, the postcodes have a one-to-one mapping with the addresses.

There are 217 postcodes in Virtual City and thus 217 addresses (IDs), as well.

PersonParams.hpp

private:
	long addressId;
	unsigned int postcode;
	int tazCode;
	double distanceBus; //km
	double distanceMRT; //km
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