UCLWilson / odjitter

Disaggregate zone-based origin/destination data to specific points

odjitter

This crate contains an implementation of the ‘jittering’ technique for pre-processing origin-destination (OD) data, plus code for conversion of aggregate OD data to disaggregate trip level data, with movement between two points represented as geographic lines that can be stored as GeoJSON files. The name comes from jittering in a data visualisation context, which refers to the addition of random noise to the location of points, preventing them overlapping.

In the context of OD data jittering refers to randomly moving start and end points associated with OD pairs, as described in an under review paper on the subject (Lovelace et al. under review). The crate is still a work in progress: the API may change. Issues and pull requests are particularly useful at this stage.

Installation

Install the package from the system command line as follows (you need to have installed and set-up cargo first):

cargo install --git https://github.com/dabreegster/odjitter

To check the package installation worked, you can run odjitter command without arguments. If it prints the following message congratulations, it works 🎉

odjitter

odjitter 0.1.0
Dustin Carlino <[e-mail]
Disaggregate origin/destination data from zones to points

USAGE:
    odjitter <SUBCOMMAND>

OPTIONS:
    -h, --help       Print help information
    -V, --version    Print version information

SUBCOMMANDS:
    disaggregate    Fully disaggregate input desire lines into output representing one trip
                    each, with a `mode` column
    help            Print this message or the help of the given subcommand(s)
    jitter          Import raw data and build an activity model for a region

As shown in the output above the odjitter command line tools has subcommands: disaggregate and jitter. The main difference between these commands is that jitter returns OD pairs representing multiple trips or fractions of a trip. disaggregate, by contrast, returns data representing single trips.

jitter OD data

To jitter OD data you need a minimum of three inputs, examples of which are provided in the data/ folder of this repo, the first few lines of which are illustrated below:

1. A .csv file containing OD data with two columns containing zone IDs (specified with --origin-key=geo_code1 --destination-key=geo_code2 by default) and other columns representing trip counts:

geo_code1	geo_code2	all	from_home	train	bus	car_driver	car_passenger	bicycle	foot	other
S02001616	S02001616	82	0	0	3	6	0	2	71	0
S02001616	S02001620	188	0	0	42	26	3	11	105	1
S02001616	S02001621	99	0	0	13	7	3	15	61	0

2. A .geojson file representing zones that contains values matching the zone IDs in the OD data (the field containing zone IDs is specified with --zone-name-key=InterZone by default):

head -6 data/zones.geojson

{
"type": "FeatureCollection",
"name": "zones_min",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
"features": [
{ "type": "Feature", "properties": { "InterZone": "S02001616", "Name": "Merchiston and Greenhill", "TotPop2011": 5018, "ResPop2011": 4730, "HHCnt2011": 2186, "StdAreaHa": 126.910911, "StdAreaKm2": 1.269109, "Shape_Leng": 9073.5402482000009, "Shape_Area": 1269109.10155 }, "geometry": { "type": "MultiPolygon", "coordinates": [ [ [ [ -3.2040366, 55.9333372 ], [ -3.2036354, 55.9321624 ], [ -3.2024036, 55.9321874 ], [ -3.2019838, 55.9315586 ], [ -3.2005071, 55.9317411 ], [ -3.199902, 55.931113 ], [ -3.2033504, 55.9308279 ], [ -3.2056319, 55.9309507 ], [ -3.2094979, 55.9308666 ], [ -3.2109753, 55.9299985 ], [ -3.2107073, 55.9285904 ], [ -3.2124928, 55.927854 ], [ -3.2125633, 55.9264661 ], [ -3.2094928, 55.9265616 ], [ -3.212929, 55.9260741 ], [ -3.2130774, 55.9264384 ], [ -3.2183973, 55.9252709 ], [ -3.2208941, 55.925282 ], [ -3.2242732, 55.9258683 ], [ -3.2279975, 55.9277452 ], [ -3.2269867, 55.928489 ], [ -3.2267625, 55.9299817 ], [ -3.2254561, 55.9307854 ], [ -3.224148, 55.9300725 ], [ -3.2197791, 55.9315472 ], [ -3.2222706, 55.9339127 ], [ -3.2224909, 55.934809 ], [ -3.2197844, 55.9354692 ], [ -3.2204535, 55.936195 ], [ -3.218362, 55.9368806 ], [ -3.2165749, 55.937069 ], [ -3.215582, 55.9380761 ], [ -3.2124132, 55.9355465 ], [ -3.212774, 55.9347972 ], [ -3.2119068, 55.9341947 ], [ -3.210138, 55.9349668 ], [ -3.208051, 55.9347716 ], [ -3.2083105, 55.9364224 ], [ -3.2053546, 55.9381495 ], [ -3.2046077, 55.9395298 ], [ -3.20356, 55.9380951 ], [ -3.2024323, 55.936318 ], [ -3.2029121, 55.935831 ], [ -3.204832, 55.9357555 ], [ -3.2040366, 55.9333372 ] ] ] ] } },

3. One or more .geojson file representing geographic entities (e.g. road networks) from which origin and destination points are sampled

head -6 data/road_network.geojson

{
"type": "FeatureCollection",
"name": "road_network_min",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
"features": [
{ "type": "Feature", "properties": { "osm_id": "3468", "name": "Albyn Place", "highway": "tertiary", "waterway": null, "aerialway": null, "barrier": null, "man_made": null, "access": null, "bicycle": null, "service": null, "z_order": 4, "other_tags": "\"lit\"=>\"yes\",\"lanes\"=>\"3\",\"maxspeed\"=>\"20 mph\",\"sidewalk\"=>\"both\",\"lanes:forward\"=>\"2\",\"lanes:backward\"=>\"1\"" }, "geometry": { "type": "LineString", "coordinates": [ [ -3.207438, 55.9533584 ], [ -3.2065953, 55.9535098 ] ] } },

The jitter command requires you to set the maximum number of trips for all trips in the jittered result, with the argument `disaggregation-threshold``. A value of 1 will create a line for every trip in the dataset, a value above the maximum number of trips in the ‘all’ column in the OD data will result in a jittered dataset that has the same number of desire lines (the geographic representation of OD pairs) as in the input (50 in this case).

With reference to the test data in this repo, you can run the jitter command line tool as follows:

odjitter jitter --od-csv-path data/od.csv \
  --zones-path data/zones.geojson \
  --subpoints-origins-path data/road_network.geojson \
  --subpoints-destinations-path data/road_network.geojson \
  --disaggregation-threshold 50 \
  --output-path output_max50.geojson

Scraped 7 zones from data/zones.geojson
Scraped 5073 subpoints from data/road_network.geojson
Scraped 5073 subpoints from data/road_network.geojson
Disaggregating OD data
Wrote output_max50.geojson

Try running it with a different disaggregation-threshold value (10 in the command below):

odjitter jitter --od-csv-path data/od.csv \
  --zones-path data/zones.geojson \
  --subpoints-origins-path data/road_network.geojson \
  --subpoints-destinations-path data/road_network.geojson \
  --disaggregation-threshold 50 \
  --output-path output_max10.geojson

Scraped 7 zones from data/zones.geojson
Scraped 5073 subpoints from data/road_network.geojson
Scraped 5073 subpoints from data/road_network.geojson
Disaggregating OD data
Wrote output_max10.geojson

Outputs

The figure below shows the output of the jitter commands above visually, with the left image showing unjittered results with origins and destinations going to zone centroids (as in many if not most visualisations of desire lines between zones), the central image showing the result after setting disaggregation-threshold argument to 50, and the right hand figure showing the result after setting disaggregation-threshold to 10.

Note: odjitter uses a random number generator to sample points, so the output will change each time you run it, unless you set the rng-seed, as documented in the next section.

The subpoints-origins-path and subpoints-destinations-path can be used to generate jittered desire lines that start from or go to particular points, defined in .geojson files. We will demonstrate this on a simple imaginary example:

head data/od_schools.csv

origin,destination,walk,bike,other,car
S02001616,S02001616,232,8,70,0
S02001620,S02001616,87,3,26,223
S02001621,S02001616,80,3,24,250
S02001622,S02001616,64,2,19,348
S02001623,S02001616,52,2,15,464
S02001656,S02001616,62,2,19,366
S02001660,S02001616,77,3,23,266
S02001616,S02001620,7,0,2,17
S02001620,S02001620,18,1,5,0

Set the origin, destination, and threshold keys (to car meaning that the max n. car trips per OD pair is 10 in this case) as follows:

odjitter jitter --od-csv-path data/od_schools.csv \
  --zones-path data/zones.geojson \
  --origin-key origin \
  --destination-key destination \
  --subpoints-origins-path data/road_network.geojson \
  --subpoints-destinations-path data/schools.geojson \
  --disaggregation-key car \
  --disaggregation-threshold 10 \
  --output-path output_max10_schools.geojson

Scraped 7 zones from data/zones.geojson
Scraped 5073 subpoints from data/road_network.geojson
Scraped 31 subpoints from data/schools.geojson
Disaggregating OD data
Wrote output_max10_schools.geojson

You can also set weights associated with each origin and destination in the input data. The following example weights trips to schools proportional to the values in the ‘weight’ key for each imaginary data point represented in the schools.geojson object:

odjitter jitter --od-csv-path data/od_schools.csv \
  --zones-path data/zones.geojson \
  --origin-key origin \
  --destination-key destination \
  --subpoints-origins-path data/road_network.geojson \
  --subpoints-destinations-path data/schools.geojson \
  --disaggregation-key car \
  --disaggregation-threshold 10 \
  --weight-key-destinations weight \
  --output-path output_max10_schools_with_weights.geojson

Scraped 7 zones from data/zones.geojson
Scraped 5073 subpoints from data/road_network.geojson
Scraped 31 subpoints from data/schools.geojson
Disaggregating OD data
Wrote output_max10_schools_with_weights.geojson

disaggregate OD data

Sometimes it’s useful to convert aggregate OD datasets into movement data at the trip level, with one record per trip or stage. Microsumulation or agent-based modelling in transport simulation software such as A/B Street is an example where disaggregate data may be needed. The disaggregate command does this full disaggregation work, as demonstrated below.

odjitter disaggregate --od-csv-path data/od.csv \
  --zones-path data/zones.geojson \
  --output-path output_individual.geojson

Scraped 7 zones from data/zones.geojson
Disaggregating OD data
Wrote output_individual.geojson

head output_individual.geojson

{"type":"FeatureCollection", "features":[
{"geometry":{"coordinates":[[-3.2135610613015526,55.93421097862768],[-3.212232711999157,55.93332165403505]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.2146097561854017,55.93170417067243],[-3.207398234215145,55.93226483238321]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.2092352469528884,55.933414631097314],[-3.2232443215658635,55.92984479481026]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.215268387637175,55.93346370497761],[-3.2173655585178675,55.9304200482236]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.207921236104001,55.932725149342815],[-3.204781939847086,55.93615884155918]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.2201663419808852,55.93491873446773],[-3.219780579470866,55.93501173548011]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.2149204733209626,55.936069295852164],[-3.220548578954645,55.933477325246955]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.2175899526711524,55.93217765442912],[-3.2194225271063255,55.92798121836583]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},
{"geometry":{"coordinates":[[-3.2040507101538713,55.93093756507587],[-3.2260899147288638,55.92866578865467]],"type":"LineString"},"properties":{"mode":"foot"},"type":"Feature"},

Details

For full details on the arguments of each of odjitter’s subcommands can be viewed with the --help flag:

odjitter jitter --help
odjitter disaggregate --help

odjitter-jitter 
Import raw data and build an activity model for a region

USAGE:
    odjitter jitter [OPTIONS] --od-csv-path <OD_CSV_PATH> --zones-path <ZONES_PATH> --output-path <OUTPUT_PATH> --disaggregation-threshold <DISAGGREGATION_THRESHOLD>

OPTIONS:
        --destination-key <DESTINATION_KEY>
            Which column in the OD row specifies the zone where trips ends? [default: geo_code2]

        --disaggregation-key <DISAGGREGATION_KEY>
            Which column in the OD row specifies the total number of trips to disaggregate?
            [default: all]

        --disaggregation-threshold <DISAGGREGATION_THRESHOLD>
            What's the maximum number of trips per output OD row that's allowed? If an input OD row
            contains less than this, it will appear in the output without transformation. Otherwise,
            the input row is repeated until the sum matches the original value, but each output row
            obeys this maximum

    -h, --help
            Print help information

        --min-distance-meters <MIN_DISTANCE_METERS>
            Guarantee that jittered origin and destination points are at least this distance apart
            [default: 1.0]

        --od-csv-path <OD_CSV_PATH>
            The path to a CSV file with aggregated origin/destination data

        --origin-key <ORIGIN_KEY>
            Which column in the OD row specifies the zone where trips originate? [default:
            geo_code1]

        --output-path <OUTPUT_PATH>
            The path to a GeoJSON file where the output will be written

        --rng-seed <RNG_SEED>
            By default, the output will be different every time the tool is run, based on a
            different random number generator seed. Specify this to get deterministic behavior,
            given the same input

        --subpoints-destinations-path <SUBPOINTS_DESTINATIONS_PATH>
            The path to a GeoJSON file to use for sampling subpoints for destination zones. If this
            isn't specified, random points within each zone will be used instead

        --subpoints-origins-path <SUBPOINTS_ORIGINS_PATH>
            The path to a GeoJSON file to use for sampling subpoints for origin zones. If this isn't
            specified, random points within each zone will be used instead

        --weight-key-destinations <WEIGHT_KEY_DESTINATIONS>
            If specified, this column will be used to more frequently choose subpoints in
            `subpoints_destinations_path` with a higher weight value. Otherwise all subpoints will
            be equally likely to be chosen

        --weight-key-origins <WEIGHT_KEY_ORIGINS>
            If specified, this column will be used to more frequently choose subpoints in
            `subpoints_origins_path` with a higher weight value. Otherwise all subpoints will be
            equally likely to be chosen

        --zone-name-key <ZONE_NAME_KEY>
            In the zones GeoJSON file, which property is the name of a zone [default: InterZone]

        --zones-path <ZONES_PATH>
            The path to a GeoJSON file with named zones
odjitter-disaggregate 
Fully disaggregate input desire lines into output representing one trip each, with a `mode` column

USAGE:
    odjitter disaggregate [OPTIONS] --od-csv-path <OD_CSV_PATH> --zones-path <ZONES_PATH> --output-path <OUTPUT_PATH>

OPTIONS:
        --destination-key <DESTINATION_KEY>
            Which column in the OD row specifies the zone where trips ends? [default: geo_code2]

    -h, --help
            Print help information

        --min-distance-meters <MIN_DISTANCE_METERS>
            Guarantee that jittered origin and destination points are at least this distance apart
            [default: 1.0]

        --od-csv-path <OD_CSV_PATH>
            The path to a CSV file with aggregated origin/destination data

        --origin-key <ORIGIN_KEY>
            Which column in the OD row specifies the zone where trips originate? [default:
            geo_code1]

        --output-path <OUTPUT_PATH>
            The path to a GeoJSON file where the output will be written

        --rng-seed <RNG_SEED>
            By default, the output will be different every time the tool is run, based on a
            different random number generator seed. Specify this to get deterministic behavior,
            given the same input

        --subpoints-destinations-path <SUBPOINTS_DESTINATIONS_PATH>
            The path to a GeoJSON file to use for sampling subpoints for destination zones. If this
            isn't specified, random points within each zone will be used instead

        --subpoints-origins-path <SUBPOINTS_ORIGINS_PATH>
            The path to a GeoJSON file to use for sampling subpoints for origin zones. If this isn't
            specified, random points within each zone will be used instead

        --weight-key-destinations <WEIGHT_KEY_DESTINATIONS>
            If specified, this column will be used to more frequently choose subpoints in
            `subpoints_destinations_path` with a higher weight value. Otherwise all subpoints will
            be equally likely to be chosen

        --weight-key-origins <WEIGHT_KEY_ORIGINS>
            If specified, this column will be used to more frequently choose subpoints in
            `subpoints_origins_path` with a higher weight value. Otherwise all subpoints will be
            equally likely to be chosen

        --zone-name-key <ZONE_NAME_KEY>
            In the zones GeoJSON file, which property is the name of a zone [default: InterZone]

        --zones-path <ZONES_PATH>
            The path to a GeoJSON file with named zones

Similar work

The technique is implemented in the function od_jitter() from the R package od. The functionality contained in this repo is an extended and much faster implementation: according to our benchmarks on a large dataset it was around 1000 times faster than the R implementation.

References

Lovelace, Robin, Rosa Félix, and Dustin Carlino Under Review Jittering: A Computationally Efficient Method for Generating Realistic Route Networks from Origin-Destination Data. TBC.