Time-Distance Matrix service API reference¶
Valhalla's time-distance matrix service provides a quick computation of time and distance between a set of locations and returns them to you in the resulting matrix table.
Matrix service¶
The time distance matrix service takes a sources and targets to list locations. This allows you to set the source (origin) locations separately from the target (destination) locations. The set of origins may be disjoint (not overlapping) with the set of destinations. In other words, the target locations do not have to include any locations from source locations. The time-distance matrix can return a row matrix, a column matrix, or a general matrix of computed time and distance, depending on your input for the sources and targets parameters. The general case is a row ordered matrix with the time and distance from each source location to each target location. A row vector is considered a one_to_many time-distance matrix where there is one source location and multiple target locations. The time and distance from the source location to all target locations is returned. A column matrix represents a many_to_one time-distance matrix where there are many sources and one target. Another special case is when the source location list is the same as the target location list. Here, a diagonal (square matrix with [0,0.00] on the diagonal elements) matrix is returned. The is special case is often used as the input to optimized routing problems.
Inputs of the matrix service¶
The matrix request run locally takes the form of localhost:8002/sources_to_targets?json={}, where the JSON inputs inside the {} includes at least one location for both sources and for targets as well as the route costing type and options for the route costing model.
For example, while at your office, you want to know the times and distances to walk to several restaurants where you could have dinner, as well as the times and distances from each restaurant to the train station for your commute home. This will help you determine where to eat.
one-to-many using /sources_to_targets?
{"sources":[{"lat":40.744014,"lon":-73.990508}],"targets":[{"lat":40.744014,"lon":-73.990508},{"lat":40.739735,"lon":-73.979713},{"lat":40.752522,"lon":-73.985015},{"lat":40.750117,"lon":-73.983704},{"lat":40.750552,"lon":-73.993519}],"costing":"pedestrian"}
many-to-one using /sources_to_targets?
{"sources":[{"lat":40.744014,"lon":-73.990508},{"lat":40.739735,"lon":-73.979713},{"lat":40.752522,"lon":-73.985015},{"lat":40.750117,"lon":-73.983704},{"lat":40.750552,"lon":-73.993519}],"targets":[{"lat":40.750552,"lon":-73.993519}],"costing":"pedestrian"}
many-to-many using /sources_to_targets?
{"sources":[{"lat":40.744014,"lon":-73.990508},{"lat":40.739735,"lon":-73.979713},{"lat":40.752522,"lon":-73.985015},{"lat":40.750117,"lon":-73.983704},{"lat":40.750552,"lon":-73.993519}],"targets":[{"lat":40.744014,"lon":-73.990508},{"lat":40.739735,"lon":-73.979713},{"lat":40.752522,"lon":-73.985015},{"lat":40.750117,"lon":-73.983704},{"lat":40.750552,"lon":-73.993519}],"costing":"pedestrian"}
Source and target parameters¶
When using the sources_to_targets action, you specify sources and targets as ordered lists of one or more locations within a JSON array, depending on the type of matrix result you are expecting.
A source and target must include a latitude and longitude in decimal degrees. The coordinates can come from many input sources, such as a GPS location, a point or a click on a map, a geocoding service, and so on.
| Source and target parameters | Description |
|---|---|
lat |
Latitude of the source/target in degrees. |
lon |
Longitude of the source/target in degrees. |
date_time |
Expected date/time for the user to be at the location using the ISO 8601 format (YYYY-MM-DDThh:mm) in the local time zone of departure or arrival. date_time as location input offers more granularity over setting time than the global date_time object (see below). |
You can refer to the route location documentation for more information on specifying locations.
Note: date_time strings behave differently for sources_to_targets than for route. If set on the sources and there's more targets than sources, it'll behave like a "Specified departure time" on the sources. If set on the targets and there's less targets than sources, it'll behave like a "Specified arrival time" on the targets.
Also, using type in addition to the lat and lon within the location parameter has no meaning for matrices.
Costing parameters¶
The Time-Distance Matrix service uses the auto, bicycle, pedestrian and bikeshare and other costing models available in the route service. Exception: multimodal costing is not supported for the time-distance matrix service at this time. Refer to the route costing models and costing options documentation for more on how to specify this input.
Other request options¶
| Options | Description |
|---|---|
id |
Name your matrix request. If id is specified, the naming will be sent thru to the response. |
matrix_locations |
For one-to-many or many-to-one requests this specifies the minimum number of locations that satisfy the request. However, when specified, this option allows a partial result to be returned. This is basically equivalent to "find the closest/best matrix_locations locations out of the full location set". |
date_time |
This is the local date and time at the location.
|
verbose |
If true it will output a flat list of objects for distances & durations explicitly specifying the source & target indices. If false will return more compact, nested row-major distances & durations arrays and not echo sources and targets. Default true. |
shape_format |
Specifies the optional format for the path shape of each connection. One of polyline6, polyline5, geojson or no_shape (default). |
Time-dependent matrices¶
Most control can be achieved when setting a date_time string on each source or target. When setting the global date_time object as a shortcut instead, Valhalla will translate that to setting the date_time.value on all source locations when date_time.type = 0/1 and on all target locations when date_time.type = 2.
However, there are important limitations of the /sources_to_targets service's time awareness. Due to algorithmic complexity, we disallow time-dependence for certain combinations of date_time on locations, if
- date_time.type = 0/1 or date_time on any source, when there's more sources than targets
- date_time.type = 2 or date_time on any target, when there's more or equal amount of targets than/as sources
Outputs of the matrix service¶
If a matrix request has been named using the optional &id= input, then the name will be returned as a string id.
These are the results of a request to the Time-Distance Matrix service.
| Item | Description |
|---|---|
sources_to_targets |
Returns an array of time and distance between the sources and the targets. The array is row-ordered. This means that the time and distance from the first location to all others forms the first row of the array, followed by the time and distance from the second source location to all target locations, etc. |
distance |
The computed distance between each set of points. Distance will always be 0.00 for the first element of the time-distance array for one_to_many, the last element in a many_to_one, and the first and last elements of a many_to_many. |
time |
The computed time between each set of points. Time will always be 0 for the first element of the time-distance array for one_to_many, the last element in a many_to_one, and the first and last elements of a many_to_many. |
to_index |
The destination index into the locations array. |
from_index |
The origin index into the locations array. |
date_time |
(optional) If the date_time was valid for an origin, date_time will return the local time at the destination. |
locations |
The specified array of lat/lngs from the input request. |
units |
Distance units for output. Allowable unit types are mi (miles) and km (kilometers). If no unit type is specified, the units default to kilometers. |
warnings (optional) |
This array may contain warning objects informing about deprecated request parameters, clamped values etc. |
See the HTTP return codes for more on messages you might receive from the service.