A class to compute the task dependencies of multiple fish cohort tasks. More...

#include <SeapodymCohortDependencyAnalyzer.h>

Public Member Functions
	SeapodymCohortDependencyAnalyzer (int numAgeGroups, int numTimeSteps, int ageMature=0, bool aPlusCohort=false)
int	getNumberOfCohorts () const
int	getNumberOfCohortSteps () const
std::map< int, int >	getStepBegMap () const
std::map< int, int >	getStepEndMap () const
std::map< int, std::set< std::array< int, 2 > > >	getDependencyMap () const
int	getFirstAPlusCohortId () const

Detailed Description

A class to compute the task dependencies of multiple fish cohort tasks.

A fish cohort is a population of fish that were born in the same interval of time. A task evolves a fish cohort over multiple time steps. After some time steps, the cohort is removed from the population and a new cohort is being born by combining the biomass of the cohorts from the previous time step. For instance, let there be 3 starting age groups (0, 1 and 2) whose populations are modelled over 5 time steps. This can be represented as:

(0,2) (1,1) (2,0) (7,0)
(3,0) (1,2) (2,1) (8,0)
(3,1) (4,0) (2,2) (9,0)
(3,2) (4,1) (5,0) (10,0)
(6,0) (4,2) (5,1) (11,0)

(here numAgeGroups=3, numTimeSteps=5, so f = getFirstAPlusCohortId() = 7; the last column is the A+ cohort f+t at time row t) where (i=cohort, j=step). The horizontal axis represents the different age groups (in this case 3) and the vertical axis is time. At each time step a new cohort is born. A+ cohorts are appended as ordinary, positive Ids right after the last normal Id (i.e. Ids numAgeGroups+numTimeSteps-1 .. numAgeGroups+2*numTimeSteps-2) and run for only one step each, just like the initial cohorts (0..numAgeGroups-1). Use getFirstAPlusCohortId() to find where the A+ Ids start.

Note that normal cohorts (excluding A+) have i + j = const across a row. A+ cohorts always have j=0.

Let f = getFirstAPlusCohortId() (= numAgeGroups+numTimeSteps-1). Then A+ cohort f+t represents the "plus group" accumulated through time step t. Initially, (0,2) (1,1) (2,0) (f,0) have no dependency and can be started immediately. Any new, "living" cohort depends on cohorts which have attained a maturity age "am" at the previous time step (in addition to the A+ cohort, if present). If am == 1 then (3,0) depends on (0,2) (1,1) (f,0) (4,0) depends on (1,2) (2,1) (f+1,0) (5,0) depends on (3,1) (2,2) (f+2,0)

Therefore (i, 0) depends on (i-j-1, j) for j = am...na-1, and on (f+(i-na), 0). The A+ chain itself is (f+t, 0) depends on (t-1, na-1) and (f+t-1, 0) for t = 1...nt-1.

Constructor & Destructor Documentation

◆ SeapodymCohortDependencyAnalyzer()

SeapodymCohortDependencyAnalyzer::SeapodymCohortDependencyAnalyzer	(	int	numAgeGroups,
		int	numTimeSteps,
		int	ageMature = 0,
		bool	aPlusCohort = false )

Constructor

Parameters

numAgeGroups	number of normal age groups, excluding the A+ "plus group" (e.g. 3 in the above example; A+, if requested, is on top of these 3)
numTimeSteps	number of tiem steps (e.g. 5 in the above example)
ageMature	index of the first mature age class. A newborn cohort only needs the densities of mature age classes (ageMature..numAgeGroups-1) of the previous time step, so dependencies on younger ages are omitted. Defaults to 0 = dependence on the full state at time t-1.
aPlusCohort	whether to add the A+ cohort dependency

Member Function Documentation

◆ getDependencyMap()

std::map< int, std::set< std::array< int, 2 > > > SeapodymCohortDependencyAnalyzer::getDependencyMap ( ) const

Get the dependency map

Returns: Id: {(Id, step), ...} map

◆ getFirstAPlusCohortId()

int SeapodymCohortDependencyAnalyzer::getFirstAPlusCohortId ( ) const

Get the Id of the first A+ cohort, i.e. the threshold above which (and including) cohort Ids represent A+ cohorts.

Equal to numAgeGroups + numTimeSteps - 1, regardless of whether aPlusCohort was requested. If aPlusCohort is false, no Ids >= this value exist. A consumer can test id >= getFirstAPlusCohortId() in place of the old id < 0 check.

Returns: Id

◆ getNumberOfCohorts()

int SeapodymCohortDependencyAnalyzer::getNumberOfCohorts ( ) const

Get the total number of cohorts (normal + A+ if aPlusCohort=true)

In the above example without A+: 7 cohorts (Ids 0..6). With A+: 7 + 5 = 12 cohorts (Ids 0..6 normal, Ids 7..11 are the A+ cohorts).

Returns: number

◆ getNumberOfCohortSteps()

int SeapodymCohortDependencyAnalyzer::getNumberOfCohortSteps ( ) const

Get the total number of cohort steps across all cohorts

In the above example without A+: 5*3 = 15 steps. With A+: 5*3 + 5 = 20 steps.

Returns: number

◆ getStepBegMap()

std::map< int, int > SeapodymCohortDependencyAnalyzer::getStepBegMap ( ) const

Get the cohort Id to first step index map

In the above example (normal cohorts): 0->2, 1->1, 2->0, 3->0, 4->0, 5->0, 6->0. A+ cohorts (if present) all map to 0: 7->0, 8->0, ..., 11->0.

Returns: Id to number map

◆ getStepEndMap()

std::map< int, int > SeapodymCohortDependencyAnalyzer::getStepEndMap ( ) const

Get the cohort Id to last step + 1 map

In the above example (normal cohorts): 0->3, 1->3, 2->3, 3->3, 4->3, 5->2, 6->1. A+ cohorts (if present) all map to 1: 7->1, 8->1, ..., 11->1.

Returns: Id to number map

The documentation for this class was generated from the following files:

src/SeapodymCohortDependencyAnalyzer.h
src/SeapodymCohortDependencyAnalyzer.cpp

Public Member Functions