GrassManager

The class GrassManager iis derivedfrom Action and serves as a growth controller for populations whose agents have a mass member, This class has been tailored for the use with GrassPop (see QHG Tutorial 08 - Simple Predator-Prey).

This class lets the mass of all agents grow logistically up to a maximum attainable mass.

It fills the shared array “” with the available masses in each xell, where available mass = actual mass - minimum mass.

Code:
GrassManager.h
GrassManager.cpp

Attributes

ATTR_GRASSMAN_NAME

“GrassManager”

action name

ATTR_GRASSMAN_MIN_MASS_NAME

“MinMass”

minimum mass

ATTR_GRASSMAN_MAX_MASS_NAME

“MaxMass”

maximum attainable mass

ATTR_GRASSMAN_GROWTH_RATE_NAME

“GrowthRate”

growth rate

Public Methods

constructor

GrassManager(SPopulation<T> *pPop, SCellGrid *pCG, std::string sID,
             const std::string sNameGrassMassAvail, const std::string sNameGrassMassConsumed);
pPop

A pointer to the SPopulation object performing this action.

pCG

A pointer to the SCellGrid object on which the simulation runs.

sID

An ID for this action.

sNameGrassMassAvail

Name of the shared array containing the per-cell available grass masses.

sNameGrassMassConsumed

Name of the shared array containing the per-cell consumed grass masses.

destructor

virtual ~GrassManager();

The destructor destroy some openMP locks.

preLoop

virtual int preLoop();

Loads the shared arrays and fills the array of available grass mass.

execute

virtual int execute(int iAgentIndex, float fT);
iAgentIndex

Index of the current agent.

fT

Current simulation step.

Increases the agents mass: \(m_A = r \cdot m_A \cdot (1 - m_A/m_{max})\), where \(m_A\) is the agent’s mass, and \(r\) is the growth rate.

finalize

virtual int finalize(float fT);
fT

Current simulation step.

Removes the masses in the array of consumed masses from the corresponding agents and fills the array of available masses.

extractAttributesQDF

virtual int extractAttributesQDF(hid_t hSpeciesGroup);
hSpeciesGroup

HDF handle for the species group to read from.

This method reads the atttributes of this action from a QDF.

writeAttributesQDF

virtual int writeAttributesQDF(hid_t hSpeciesGroup);
hSpeciesGroup

HDF handle for the species group to write to.

This method writes the attributes of this action to the specified group in a QDF file.

tryGetAttributes

virtual int tryGetAttributes(const ModuleComplex *pMC);
pMC

A ModuleComplex object.

Extracts the action’s attributes from the ModuleComplex object.

modifyAttributes

virtual int modifyAttributes(const std::string sAttrName, double dValue);
sAttrName`

Name of attribute to change.

dValue

Value to set the attribute to.

This method can change the values of \(m_{min}\) (ATTR_GRASSMAN_MIN_MASS_NAME), \(m_{max}\) (ATTR_GRASSMAN_MAX_MASS_NAME), or \(r\) (ATTR_GRASSMAN_GROWTH_RATE_NAME).

isEqual

virtual bool isEqual(Action<T> *pAction, bool bStrict);
pAction

Pointer to an action object to compare with this.

bStrict

Strictness of comparisons (ignored here).

pAction is equal to this, if it is a GrassManager object whose attributes match those of this.