Getting Started¶
Once you have installed smif, the quickest way to get started is to use the included sample project. You can make a new directory and copy the sample project files there by running:
$ mkdir sample_project
$ cd sample_project
$ smif setup
$ ls
config/ data/ models/ planning/ results/ smif.log
On the command line, from within the project directory, type the following command to list the available model runs:
$ smif list
20170918_energy_water_short
20170918_energy_water
To run a model run, type the following command:
$ smif run 20170918_energy_water
Model run complete
Note that the -d
directory flag can be used to point to the project folder,
so you can run smif commands explicitly:
$ smif list -d ~/projects/smif_sample_project/
...
Project Configuration¶
There are three layers of configuration in order to use the simulation modelling integration framework to conduct system-of-system modelling.
A project is the highest level container which holds all the elements required to run models, configure simulation models and define system-of-system models.
The basic folder structure looks like this:
/config
project.yml
/sector_models
energy_demand.yml
water_supply.yml
/sos_models
energy_water.yml
/sos_model_runs
20170918_energy_water.yml
20170918_energy_water_short.yml
/data
/initial_conditions
energy_demand_existing.yml
energy_supply_existing.yml
/interval_definitions
hourly.csv
annual.csv
/interventions
energy_demand.yml
/narratives
energy_demand_high_tech.yml
central_planning.yml
/region_definitions
lad.shp
/scenarios
population_high.csv
/models
energy_demand.py
water_supply.py
/results
/20170918_energy_water_short
/energy_demand
/water_supply
The folder structure is divided into a config
subfolder and a data
subfolder.
The Configuration Folder¶
This folder holds configuration and metadata on simulation models, system-of-system models and model runs.
The Project File¶
This file holds all the project configuration.
name: Test Project
scenario_sets:
- description: Growth in UK population
facets:
- name: population
description: ''
name: population
- description: Rainfall in the UK
facets:
- name: raininess
description: ''
name: rainfall
narrative_sets:
- description: Describes the evolution of technology
name: technology
interval_definitions:
- description: ''
filename: annual_intervals.csv
name: annual
narratives:
- description: High penetration of SMART technology on the demand side
filename: high_tech_dsm.yml
name: High Tech Demand Side Management
narrative_set: technology
region_definitions:
- description: ''
filename: uk_nations_shp/regions.shp
name: national
- description: ''
filename: oxfordshire/regions.geojson
name: oxfordshire
scenarios:
- description: ''
facets:
- filename: raininess.csv
name: raininess
spatial_resolution: national
temporal_resolution: annual
units: litre
name: Central Rainfall
scenario_set: rainfall
- description: ''
facets:
- filename: population_low.csv
name: population
spatial_resolution: national
temporal_resolution: annual
units: people
name: Central Population (Low)
scenario_set: population
- description: ''
facets:
- filename: population_med.csv
name: population
spatial_resolution: national
temporal_resolution: annual
units: people
name: Central Population (Medium)
scenario_set: population
- description: ''
facets:
- filename: population_high.csv
name: population
spatial_resolution: national
temporal_resolution: annual
units: people
name: Central Population (High)
scenario_set: population
units: units.txt
We’ll step through this configuration file section by section.
The first line gives the project name, a unique identifier for this project.
name: Test Project
One section lists the scenario sets. These give the categories into which scenarios are collected.
scenario_sets:
- description: Growth in UK population
facets:
- name: population
description: ''
name: population
Narrative sets collect together the categories into which narrative files are collected.
narrative_sets:
- description: Describes the evolution of technology
name: technology
Region definitions list the collection of region files and the mapping to a unique name which can be used in scenarios and sector models. Region definitions define the spatial resolution of data.
region_definitions:
- description: ''
filename: uk_nations_shp/regions.shp
name: national
Interval definitions list the collection of interval files and the mapping to a unique name which can be used in scenarios and sector models. Interval definitions define the temporal resolution of data.
interval_definitions:
- description: ''
filename: annual_intervals.csv
name: annual
Unit definitions references a file containing custom units, not included in the Pint library default unit register (e.g. non-SI units).
units: units.txt
The scenarios
section lists the scenarios and corresponding collections of
data associated with scenarios.
scenarios:
- description: ''
facets:
- filename: raininess.csv
name: raininess
spatial_resolution: national
temporal_resolution: annual
units: litre
name: Central Rainfall
scenario_set: rainfall
The narratives
section lists the narratives and mapping to one or more
narrative files
narratives:
- description: High penetration of SMART technology on the demand side
filename: high_tech_dsm.yml
name: High Tech Demand Side Management
narrative_set: technology
A Simulation Model File¶
A simulation model file contains all the configuration data necessary for smif to run the model, and link the model to data sources and sinks. This file also contains a list of parameters, the ‘knobs and dials’ the user wishes to expose to smif which can be adjusted in narratives. Intervention files and initial condition files contain the collections of data that are needed to expose the model to smif’s decision making functionality.
name: water_supply # model name for internal/logging reference
description: 'Simulates the optimal operation of the UK water
supply system'
path: models/water_supply.py # path to python file
classname: WaterSupplySectorModel # implements smif.SectorModel
inputs:
- name: raininess
spatial_resolution: national
temporal_resolution: annual
units: Ml
- name: population
spatial_resolution: national
temporal_resolution: annual
units: people
- name: water_demand
spatial_resolution: national
temporal_resolution: annual
units: Ml
outputs:
- name: cost
spatial_resolution: national
temporal_resolution: annual
units: million GBP
- name: energy_demand
spatial_resolution: national
temporal_resolution: annual
units: kWh
- name: water
spatial_resolution: national
temporal_resolution: annual
units: Ml
interventions:
- water_supply.yml
initial_conditions:
- water_supply_oxford.yml
- reservoirs.yml
parameters:
- name: clever_water_meter_savings
description: The savings from smart water meters
absolute_range: (0, 100)
suggested_range: (3, 10)
default_value: 3
units: '%'
- name: per_capita_water_demand
description: The assumed per capita demand for water
absolute_range: (0, 1.5)
suggested_range: (1, 1.3)
default_value: 1.1
units: 'liter/person'
Inputs¶
Define the collection of inputs required from external sources to run the model. Inputs are defined with a name, spatial resolution, temporal-resolution and units.
inputs:
- name: raininess
spatial_resolution: national
temporal_resolution: annual
units: Ml
- name: population
spatial_resolution: national
temporal_resolution: annual
units: people
Attribute | Type | Notes |
---|---|---|
name | string | A unique name within the input defintions |
spatial_resolution | string | References an entry in the region definitions |
temporal_resolution | string | References an entry in the interval definitions |
units | string | References an entry in the unit definitions |
Outputs¶
Define the collection of output model parameters used for the purpose of metrics, for accounting purposes, such as operational cost and emissions, or as the source of a dependency in another model.
outputs:
- name: cost
spatial_resolution: national
temporal_resolution: annual
units: million GBP
- name: energy_demand
spatial_resolution: national
temporal_resolution: annual
units: kWh
Attribute | Type | Notes |
---|---|---|
name | string | A unique name within the output definitions |
spatial_resolution | string | References an entry in the region definitions |
temporal_resolution | string | References an entry in the interval definitions |
units | string | References an entry in the unit definitions |
Parameters¶
parameters:
- name: clever_water_meter_savings
description: The savings from smart water meters
absolute_range: (0, 100)
suggested_range: (3, 10)
default_value: 3
units: '%'
Attribute | Type | Notes |
---|---|---|
name | string | A unique name within the simulation model |
description | string | Include sources of assumptions around default value |
absolute_range | tuple | Raises an error if bounds exceeded |
suggested_range | tuple | Provides a hint to a user as to sensible ranges |
default_value | float | The default value for the parameter |
units | string |
A System-of-System Model File¶
A system-of-systems model collects together scenario sets and simulation models. Users define dependencies between scenario and simulation models.
name: energy_water
description: 'The future supply and demand of energy and water for the UK'
scenario_sets: # Select 0 or more of the scenario sets
- population
- rainfall
narrative_sets: []
sector_models: # Select 1 or more of the sector models
- water_supply
- energy_demand
dependencies:
- source_model: rainfall
source_model_output: raininess
sink_model: water_supply
sink_model_input: raininess
- source_model: population
source_model_output: population
sink_model: water_supply
sink_model_input: population
- source_model: water_supply
source_model_output: energy_demand
sink_model: energy_demand
sink_model_input: energy_demand
- source_model: population
source_model_output: population
sink_model: energy_demand
sink_model_input: population
- source_model: energy_demand
source_model_output: water_demand
sink_model: water_supply
sink_model_input: water_demand
max_iterations: 100
convergence_absolute_tolerance: 1e-05
convergence_relative_tolerance: 1e-05
Scenario Sets¶
Scenario sets are the categories in which scenario data are organised. Choosing a scenario set at this points allows different scenario data to be chosen in model runs which share the same system-of-systems model configuration defintion.
scenario_sets: # Select 0 or more of the scenario sets
- population
- rainfall
Attribute | Type | Notes |
---|---|---|
names | list | A list of scenario set names |
Simulation Models¶
This section contains a list of pre-configured simulation models which exist in the current project.
narrative_sets: []
sector_models: # Select 1 or more of the sector models
- water_supply
Attribute | Type | Notes |
---|---|---|
names | list | A list of simulation model names |
Dependencies¶
In this section, dependencies are defined between sources and sinks.
- energy_demand
dependencies:
- source_model: rainfall
source_model_output: raininess
sink_model: water_supply
sink_model_input: raininess
- source_model: population
source_model_output: population
sink_model: water_supply
Attribute | Type | Notes |
---|---|---|
source_model | string | The source model of the data |
source_model_output | string | The output in the source model |
sink_model | string | The model which depends on the source |
sink_model_input | string | The input which should receive the data |
A Model Run File¶
A model run brings together a system-of-systems model definition with timesteps over which planning takes place, and a choice of scenarios and narratives to population the placeholder scenario sets in the system-of-systems model.
name: 20170918_energy_water
description: Combined energy and water under central scenario
stamp: "2017-09-18T12:53:23+00:00"
timesteps:
- 2010
- 2015
- 2020
sos_model: energy_water
decision_module: ''
scenarios:
population: Central Population (Medium)
rainfall: Central Rainfall
narratives:
technology:
- High Tech Demand Side Management
Timesteps¶
A list of timesteps define the years in which planning takes place, and the simulation models are executed.
timesteps:
- 2010
- 2015
- 2020
Attribute | Type | Notes |
---|---|---|
timesteps | list | A list of integer years |
Scenarios¶
For each scenario set available in the contained system-of-systems model, one scenario should be chosen.
scenarios:
population: Central Population (Medium)
rainfall: Central Rainfall
Attribute | Type | Notes |
---|---|---|
scenarios | list | A list of tuples of scenario sets and scenarios |
Narratives¶
For each narrative set available in the project, zero or more available narratives should be chosen.
narratives:
technology:
- High Tech Demand Side Management
Note that narrative files override the values of parameters in specific simulation models. Selecting a narrative file which overrides parameters in an absent simulation model will have no effect.
Attribute | Type | Notes |
---|---|---|
scenarios | list | A list of mappings between narrative sets and list of narrative files |
Data Folder¶
This folder holds data like information to define the spatial and temporal resolution of data, as well as exogenous environmental data held in scenarios.
Initial Conditions¶
- name: Kielder Water
location: England
capacity:
value: 500
units: ML
operational_lifetime:
value: 300
units: years
economic_lifetime:
value: 150
units: years
capital_cost:
value: 15
units: million £
build_date: 1975
current_level:
value: 3
units: Ml
is_state: true
Interval definitions¶
The attribution of hours in a year to the temporal resolution used in the sectoral model.
Within-year time intervals are specified in yaml files, and as for regions,
specified in the *.yml
file in the project/data/intervals
folder.
This links a unique name with the definitions of the intervals in a yaml file. The data in the file specify the mapping of model timesteps to durations within a year (assume modelling 365 days: no extra day in leap years, no leap seconds)
Use ISO 8601 [1] duration format to specify periods:
P[n]Y[n]M[n]DT[n]H[n]M[n]S
For example:
id,start,end
1,PT0H,PT8760H
In this example, the interval with id 1
begins in the first hour of the year
and ends in the last hour of the year. This represents one, year-long interval.
Attribute | Type | Notes |
---|---|---|
id | string | The unique identifier used by the simulation model |
start_hour | string | Period since beginning of year |
end_hour | string | Period since beginning of year |
Region definitions¶
Define the set of unique regions which are used within the model as polygons. The spatial resolution of the model may be implicit, and even a national model needs to have a national region defined. Inputs and outputs are assigned a model-specific geography from this list allowing automatic conversion from and to these geographies.
Model region files are stored in project/data/region_defintions
.
The file format must be possible to parse with GDAL, and must contain an attribute “name” to use as an identifier for the region.
The sets of geographic regions are specified in the project configuration file
using a region_definitions
attributes as shown below:
- name: raininess
name: rainfall
narrative_sets:
- description: Describes the evolution of technology
name: technology
interval_definitions:
- description: ''
This links a name, used elsewhere in the configuration with inputs, outputs and scenarios with a file containing the geographic data.
Interventions¶
Interventions are the atomic units which comprise the infrastructure systems in the simulation models. Interventions can represent physical assets such as pipes, and lines (edges in a network) or power stations and reservoirs (nodes in a network). Interventions can also represent intangibles which affects the operation of a system, such as a policy.
An exhaustive list of the interventions (often infrastructure assets)
should be defined.
These are represented internally in the system-of-systems model,
collected into a gazateer and allow the framework to reason on
infrastructure assets across all sectors.
Interventions are instances of Intervention
and are
held in InterventionRegister
.
Interventions include investments in assets,
supply side efficiency improvements, but not demand side management (these
are incorporated in the strategies).
Define all possible interventions in an *.yml
file
in the project/data/interventions
For example:
- name: small_pumping_station
location: Oxford
capacity:
value: 50
units: ML/day
operational_lifetime:
value: 150
units: years
economic_lifetime:
value: 50
units: years
capital_cost:
value: 5
units: million £
Narratives¶
A narrative file contains references to 0 or more parameters defined in the
simulation models, as well as special global
parameters. Whereas model
parameters are available only to individual simulation models,
global parameters are available across all models.
Use global paramaters for system-wide constants, such as emission coefficients,
exchange rates, conversion factors etc.
Value specified in the narrative file override the default values specified in the simulation model configuration. If more than one narrative file is selected in the sos model configuration, then values in later files override values in earlier files.
energy_demand:
smart_meter_savings: 8
water_supply:
clever_water_meter_savings: 8
per_capita_water_demand: 1.2
Scenarios¶
The scenarios:
section of the project configuration file allows
you to define static sources for simulation model dependencies.
In the case of the example project file shown earlier,
the scenarios
section lists the scenarios and corresponding collections of
data associated with the scenario sets:
narrative_set: technology
- description: ''
filename: uk_nations_shp/regions.shp
name: national
- description: ''
filename: oxfordshire/regions.geojson
name: oxfordshire
scenarios:
- description: ''
facets:
- filename: raininess.csv
name: raininess
spatial_resolution: national
temporal_resolution: annual
units: litre
name: Central Rainfall
scenario_set: rainfall
- description: ''
facets:
The data files are stored in the project/data/scenarios
folder.
The metadata required to define a particular scenario are shown in the table below. It is possible to associate a number of different data sets with the same scenario, so that, for example, choosing the High Population scenario allows users to access both population count and density data in the same or different spatial and temporal resolutions.
Attribute | Type | Notes |
---|---|---|
name | string | |
description | string | |
scenario_set | string | |
parameters | list |
Scenario Parameters¶
The filename in the parameters
section within the scenario definition
points to a comma-seperated-values file stored in the project/data/scenarios
folder. For example:
year,region,interval,value
2010,England,1,52000000
2010,Scotland,1,5100000
2010,Wales,1,2900000
2015,England,1,53000000
2015,Scotland,1,5300000
2015,Wales,1,3000000
2020,England,1,54000000
2020,Scotland,1,5500000
2020,Wales,1,3200000
For each entry in the scenario parameters list, the following metadata is required:
Attribute | Type | Notes |
---|---|---|
name | string | |
spatial_resolution | string | |
temporal_resolution | string | |
units | string | |
filename | string |
Wrapping a Sector Model: Overview¶
In addition to collecting the configuration data listed above,
to integrate a new sector model into the system-of-systems model
it is necessary to write a Python wrapper function.
The template class smif.model.sector_model.SectorModel
enables a user
to write a script which runs the wrapped model, passes in parameters and writes
out results.
The wrapper acts as an interface between the simulation modelling integration framework and the simulation model, keeping all the code necessary to implement the conversion of data types in one place.
In particular, the wrapper must take the smif formatted data, which includes
inputs, parameters, state and pass this data into the wrapped model. After the
simulate()
has run, results from
the sector model must be formatted and passed back into smif.
The handling of data is aided through the use of a set of methods provided by
smif.data_layer.data_handle.DataHandle
, namely:
and
In this section, we describe the process necessary to correctly write this wrapper function, referring to the example project included with the package.
It is difficult to provide exhaustive details for every type of sector model implementation - our decision to leave this largely up to the user is enabled by the flexibility afforded by python. The wrapper can write to a database or structured text file before running a model from a command line prompt, or import a python sector model and pass in parameters values directly. As such, what follows is a recipe of components from which you can construct a wrapper to full integrate your simulation model within smif.
For help or feature requests, please raise issues at the github repository [2] and we will endeavour to provide assistance as resources allow.
Example Wrapper¶
Here’s a reproduction of the example wrapper in the sample project included within smif. In this case, the wrapper doesn’t actually call or run a separate model, but demonstrates calls to the data handler methods necessary to pass data into an external model, and send results back to smif.
"""Energy model
"""
def initialise(self, initial_conditions):
pass
def simulate(self, data):
# Get the current timestep
now = data.current_timestep
self.logger.info("EDMWrapper received inputs in %s",
now)
# Demonstrates how to get the value for a model parameter
parameter_value = data.get_parameter('smart_meter_savings')
self.logger.info('Smart meter savings: %s', parameter_value)
# Demonstrates how to get the value for a model input
# (defaults to the current time period)
current_energy_demand = data.get_data('energy_demand')
self.logger.info("Current energy demand in %s is %s",
now, current_energy_demand)
# Demonstrates how to get the value for a model input from the base
# timeperiod
base_energy_demand = data.get_base_timestep_data('energy_demand')
base_year = data.base_timestep
self.logger.info("Base year energy demand in %s was %s", base_year,
base_energy_demand)
# Demonstrates how to get the value for a model input from the previous
# timeperiod
if now > base_year:
prev_energy_demand = data.get_previous_timestep_data('energy_demand')
prev_year = data.previous_timestep
self.logger.info("Previous energy demand in %s was %s",
prev_year, prev_energy_demand)
# Pretend to call the 'energy model'
# This code prints out debug logging messages for each input
# defined in the energy_demand configuration
for name in self.inputs.names:
time_intervals = self.inputs[name].get_interval_names()
regions = self.inputs[name].get_region_names()
for i, region in enumerate(regions):
for j, interval in enumerate(time_intervals):
self.logger.info(
"%s %s %s",
interval,
region,
data.get_data(name)[i, j])
# Write pretend results to data handler
data.set_results("cost", np.ones((3, 1)) * 3)
data.set_results("water_demand", np.ones((3, 1)) * 3)
self.logger.info("EDMWrapper produced outputs in %s",
now)
def extract_obj(self, results):
return 0
The key methods in the SectorModel class which need to be overridden are:
The wrapper should be written in a python file, e.g. water_supply.py
.
The path to the location of this file should be entered in the
sector model configuration of the project.
(see A Simulation Model File above).
Wrapping a Sector Model: Simulate¶
The most common workflow that will need to be implemented in the simulate method is:
- Retrieve model input and parameter data from the data handler
- Write or pass this data to the wrapped model
- Run the model
- Retrieve results from the model
- Write results back to the data handler
Accessing model parameter data¶
Use the get_parameter()
or
get_parameters()
method as shown in the
example:
parameter_value = data.get_parameter('smart_meter_savings')
Note that the name argument passed to the get_parameter()
is that which is defined in
the sector model configuration file.
Accessing model input data for the current year¶
The method get_data()
allows a user to
get the value for any model input that has been defined in the sector model’s
configuration. In the example, the option year argument is omitted, and it
defaults to fetching the data for the current timestep.
current_energy_demand = data.get_data('energy_demand')
Accessing model input data for the base year¶
To access model input data from the timestep prior to the current timestep, you can use the following argument:
base_energy_demand = data.get_base_timestep_data('energy_demand')
Accessing model input data for a previous year¶
To access model input data from the timestep prior to the current timestep, you can use the following argument:
prev_energy_demand = data.get_previous_timestep_data('energy_demand')
Passing model data directly to a Python model¶
If the wrapped model is a python script or package, then the wrapper can import and instantiate the model, passing in data directly.
instance = ExampleWaterSupplySimulationModel()
instance.raininess = raininess
instance.number_of_treatment_plants = number_of_treatment_plants
instance.reservoir_level = reservoir_level
water, cost = instance.run()
data.set_results('water', np.ones((3, 1)) * water / 3)
data.set_results("cost", np.ones((3, 1)) * cost / 3)
In this example, the example water supply simulation model is instantiated
within the simulate method, data is written to properties of the instantiated
class and the run()
method of the simulation model is called.
Finally, (dummy) results are written back to the data handler using the
set_results()
method.
Alternatively, the wrapper could call the model via the command line (see below).
Passing model data in as a command line argument¶
If the model is fairly simple, or requires a parameter value or input data to
be passed as an argument on the command line,
use the methods provided by subprocess
to call out to the model
from the wrapper:
parameter = data.get_parameter('command_line_argument')
arguments = ['path/to/model/executable',
'-my_argument={}'.format(parameter)]
output = subprocess.run(arguments, check=True)
Writing data to a text file¶
Again, the exact implementation of writing data to a text file for subsequent reading into the wrapped model will differ on a case-by-case basis. In the following example, we write some data to a comma-separated-values (.csv) file:
with open(path_to_data_file, 'w') as open_file:
fieldnames = ['year', 'PETROL', 'DIESEL', 'LPG',
'ELECTRICITY', 'HYDROGEN', 'HYBRID']
writer = csv.DictWriter(open_file, fieldnames)
writer.writeheader()
now = data.current_timestep
base_year_enum = RelativeTimestep.BASE
base_price_set = {
'year': base_year_enum.resolve_relative_to(now, data.timesteps),
'PETROL': data.get_data('petrol_price', base_year_enum),
'DIESEL': data.get_data('diesel_price', base_year_enum),
'LPG': data.get_data('lpg_price', base_year_enum),
'ELECTRICITY': data.get_data('electricity_price', base_year_enum),
'HYDROGEN': data.get_data('hydrogen_price', base_year_enum),
'HYBRID': data.get_data('hybrid_price', base_year_enum)
}
current_price_set = {
'year': now,
'PETROL': data.get_data('petrol_price'),
'DIESEL': data.get_data('diesel_price'),
'LPG': data.get_data('lpg_price'),
'ELECTRICITY': data.get_data('electricity_price'),
'HYDROGEN': data.get_data('hydrogen_price'),
'HYBRID': data.get_data('hybrid_price')
}
writer.writerow(base_price_set)
writer.writerow(current_price_set)
Writing data to a database¶
The exact implementation of writing input and parameter data will differ on a
case-by-case basis. In the following example, we write model inputs
energy_demand
to a postgreSQL database table ElecLoad
using the
psycopg2 library [3]
def simulate(self, data):
# Open a connection to the database
conn = psycopg2.connect("dbname=vagrant user=vagrant")
# Open a cursor to perform database operations
cur = conn.cursor()
# Returns a numpy array whose dimensions are defined by the interval and
# region definitions
elec_data = data.get_data('electricity_demand')
# Build the SQL string
sql = """INSERT INTO "ElecLoad" (Year, Interval, BusID, ElecLoad)
VALUES (%s, %s, %s, %s)"""
# Get the time interval definitions associated with the input
time_intervals = self.inputs[name].get_interval_names()
# Get the region definitions associated with the input
regions = self.inputs[name].get_region_names()
# Iterate over the regions and intervals (columns and rows) of the numpy
# array holding the energy demand data and write each value into the table
for i, region in enumerate(regions):
for j, interval in enumerate(time_intervals):
# This line calls out to a helper method which associates
# electricity grid bus bars to energy demand regions
bus_number = get_bus_number(region)
# Build the tuple to write to the table
insert_data = (data.current_timestep,
interval,
bus_number,
data[i, j])
cur.execute(sql, insert_data)
# Make the changes to the database persistent
conn.commit()
# Close communication with the database
cur.close()
conn.close()
Writing model results to the data handler¶
Writing results back to the data handler is as simple as calling the
set_results()
method:
data.set_results("cost", np.array([[1.23, 1.543, 2.355]])
The expected format of the data is a 2-dimensional numpy array with the
dimensions described by the tuple (len(regions), len(intervals))
as defined in the model’s output configuration.
Results are expected to be set for each of the model outputs defined in the
output configuration and a warning is raised if these are not present at
runtime.
The interval definitions associated with the output can be interrogated from
within the SectorModel class using self.outputs[name].get_interval_names()
and the regions using self.outputs[name].get_region_names()
and these can
then be used to compose the numpy array.