R/ab_scenario.R
ab_json.RdThis function takes outputs from ab_scenario() and returns a list that
can be saved as a JSON file for import into A/B Street.
ab_json(
desire_lines,
mode_column = NULL,
time_fun = ab_time_normal,
scenario_name = "test",
default_purpose = "Work",
...
)OD data represented as geographic lines created by
ab_scenario().
The column name in the desire lines data that contains
the mode of transport. "mode_baseline" by default.
The function used to calculate departure times.
ab_time_normal() by default.
The name of the scenario to appear in A/B Street.
The default value is "test", which generates a message to tell you to
think of a more imaginative scenario name!
In case a purpose column is not present in the input,
or there are missing values in the purpose column, this argument sets
the default, fallback purpose, as "Work" by default, reflecting the
prevalence of work-based data and thinking in transport models.
Additional arguments to pass to ab_json()
A list that can be saved as a JSON file with ab_save()
Note: the departure time in seconds is multiplied by 10000 on conversion to a .json list object for compatibility with the A/B Street schema.
# Starting with tabular data
od = leeds_od
od[[1]] = c("E02006876")
zones = leeds_zones
ablines = ab_scenario(od, zones = zones)
#> 0 origins with no match in zone ids
#> 0 destinations with no match in zone ids
#> points not in od data removed.
#> Linking to GEOS 3.9.1, GDAL 3.4.0, PROJ 8.1.1; sf_use_s2() is TRUE
ab_list = ab_json(ablines, mode_column = "mode", scenario_name = "test")
#> Default scenario name of 'test' used.
ab_list$scenario
#> [1] "test"
f = tempfile(fileext = ".json")
ab_save(ab_list, f)
readLines(f)[1:30]
#> [1] "{"
#> [2] " \"scenario_name\": \"test\","
#> [3] " \"people\": ["
#> [4] " {"
#> [5] " \"trips\": ["
#> [6] " {"
#> [7] " \"departure\": 305040000,"
#> [8] " \"origin\": {"
#> [9] " \"Position\": {"
#> [10] " \"longitude\": -1.5005,"
#> [11] " \"latitude\": 53.7681"
#> [12] " }"
#> [13] " },"
#> [14] " \"destination\": {"
#> [15] " \"Position\": {"
#> [16] " \"longitude\": -1.5583,"
#> [17] " \"latitude\": 53.8085"
#> [18] " }"
#> [19] " },"
#> [20] " \"mode\": \"Walk\","
#> [21] " \"purpose\": \"Work\""
#> [22] " }"
#> [23] " ]"
#> [24] " },"
#> [25] " {"
#> [26] " \"trips\": ["
#> [27] " {"
#> [28] " \"departure\": 294480000,"
#> [29] " \"origin\": {"
#> [30] " \"Position\": {"
# Starting with JSON data from A/B Street (multiple trips per person)
f = system.file("extdata/minimal_scenario2.json", package = "abstr")
desire_lines = ab_sf(f)
desire_lines
#> Simple feature collection with 4 features and 4 fields
#> Geometry type: LINESTRING
#> Dimension: XY
#> Bounding box: xmin: -122.319 ymin: 47.63728 xmax: -122.3037 ymax: 47.64048
#> Geodetic CRS: WGS 84
#> person departure mode purpose geometry
#> 1 1 0.1 Bike Meal LINESTRING (-122.3037 47.63...
#> 2 1 1000.0 Walk Recreation LINESTRING (-122.3191 47.63...
#> 3 2 1.1 Walk Meal LINESTRING (-122.3037 47.63...
#> 4 2 1001.0 Bike Work LINESTRING (-122.3191 47.63...
json_list = ab_json(desire_lines)
#> Default scenario name of 'test' used.
json_list
#> $scenario_name
#> [1] "test"
#>
#> $people
#> $people[[1]]
#> $people[[1]]$trips
#> $people[[1]]$trips[[1]]
#> $people[[1]]$trips[[1]]$departure
#> [1] 1000
#>
#> $people[[1]]$trips[[1]]$origin
#> $people[[1]]$trips[[1]]$origin$Position
#> $people[[1]]$trips[[1]]$origin$Position$longitude
#> [1] -122.3037
#>
#> $people[[1]]$trips[[1]]$origin$Position$latitude
#> [1] 47.63728
#>
#>
#>
#> $people[[1]]$trips[[1]]$destination
#> $people[[1]]$trips[[1]]$destination$Position
#> $people[[1]]$trips[[1]]$destination$Position$longitude
#> [1] -122.3191
#>
#> $people[[1]]$trips[[1]]$destination$Position$latitude
#> [1] 47.63786
#>
#>
#>
#> $people[[1]]$trips[[1]]$mode
#> [1] "Bike"
#>
#> $people[[1]]$trips[[1]]$purpose
#> [1] "Meal"
#>
#>
#> $people[[1]]$trips[[2]]
#> $people[[1]]$trips[[2]]$departure
#> [1] 1e+07
#>
#> $people[[1]]$trips[[2]]$origin
#> $people[[1]]$trips[[2]]$origin$Position
#> $people[[1]]$trips[[2]]$origin$Position$longitude
#> [1] -122.3191
#>
#> $people[[1]]$trips[[2]]$origin$Position$latitude
#> [1] 47.63786
#>
#>
#>
#> $people[[1]]$trips[[2]]$destination
#> $people[[1]]$trips[[2]]$destination$Position
#> $people[[1]]$trips[[2]]$destination$Position$longitude
#> [1] -122.3076
#>
#> $people[[1]]$trips[[2]]$destination$Position$latitude
#> [1] 47.63948
#>
#>
#>
#> $people[[1]]$trips[[2]]$mode
#> [1] "Walk"
#>
#> $people[[1]]$trips[[2]]$purpose
#> [1] "Recreation"
#>
#>
#>
#>
#> $people[[2]]
#> $people[[2]]$trips
#> $people[[2]]$trips[[1]]
#> $people[[2]]$trips[[1]]$departure
#> [1] 11000
#>
#> $people[[2]]$trips[[1]]$origin
#> $people[[2]]$trips[[1]]$origin$Position
#> $people[[2]]$trips[[1]]$origin$Position$longitude
#> [1] -122.3037
#>
#> $people[[2]]$trips[[1]]$origin$Position$latitude
#> [1] 47.63828
#>
#>
#>
#> $people[[2]]$trips[[1]]$destination
#> $people[[2]]$trips[[1]]$destination$Position
#> $people[[2]]$trips[[1]]$destination$Position$longitude
#> [1] -122.3191
#>
#> $people[[2]]$trips[[1]]$destination$Position$latitude
#> [1] 47.63886
#>
#>
#>
#> $people[[2]]$trips[[1]]$mode
#> [1] "Walk"
#>
#> $people[[2]]$trips[[1]]$purpose
#> [1] "Meal"
#>
#>
#> $people[[2]]$trips[[2]]
#> $people[[2]]$trips[[2]]$departure
#> [1] 10010000
#>
#> $people[[2]]$trips[[2]]$origin
#> $people[[2]]$trips[[2]]$origin$Position
#> $people[[2]]$trips[[2]]$origin$Position$longitude
#> [1] -122.3191
#>
#> $people[[2]]$trips[[2]]$origin$Position$latitude
#> [1] 47.63886
#>
#>
#>
#> $people[[2]]$trips[[2]]$destination
#> $people[[2]]$trips[[2]]$destination$Position
#> $people[[2]]$trips[[2]]$destination$Position$longitude
#> [1] -122.3076
#>
#> $people[[2]]$trips[[2]]$destination$Position$latitude
#> [1] 47.64048
#>
#>
#>
#> $people[[2]]$trips[[2]]$mode
#> [1] "Bike"
#>
#> $people[[2]]$trips[[2]]$purpose
#> [1] "Work"
#>
#>
#>
#>
#>