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queuePriority

Class:matlab.DiscreteEventSystem
Package:matlab

Define priority queue storage

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Syntax

storage=queuePriority(entityType,capacity,key,order)

Description

storage=queuePriority(entityType,capacity,key,order)defines a priority queue that sorts entities by custom attribute. Use this function when implementing thegetEntityStorageImplmethod.

Input Arguments

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Type of entities that the new storage element works with.

Maximum number of entities that the storage can contain, specified as a double.

Name of the attribute that is used as the key for sorting.

Direction of sorting. Specify'ascending'if you want entities with smaller key values to appear in front of the queue. Specify'descending'if you want entities with greater key values to appear in front of the queue.

Output Arguments

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Queue storage element that contains entities and sorts them using a custom attribute.

Examples

Define Storage Element as a Priority Queue

Define storage element as a priority queue.

% Define a storage element as a priority queue% - Queue sorts entities using a specific attribute of the entities% - Queue can store entities of type 'myEntity'% - Queue can store no more than 25 entities% - Queue uses the attribute 'age' to sort entities% - Sorting direction is 'ascending', resulting entities with% smaller 'age' attribute values to appear in front of the queuestorage = obj.queuePriority('myEntity', 25,'age','ascending');

Custom Entity Storage Block with Iteration Event

In this example, a custom block allows entities to enter its storage element through its input port. The storage element is a priority queue that sorts the entities based on theirDiameter属性按升序。每一个实体t条目o the block's storage invokes an iteration event to display the diameter and the position of each entity in the storage.

For more information, seeCreate a Custom Entity Storage Block with Iteration Event.

classdefCustomEntityStorageBlockIteration < matlab.DiscreteEventSystem% A custom entity storage block with one input port and one storage element.% Nontunable propertiesproperties(Nontunable)% CapacityCapacity = 5;end% Create the storage element with one input and one storage.methods(Access=protected)functionnum = getNumInputsImpl(obj) num = 1;endfunctionnum = getNumOutputsImpl(obj) num = 0;endfunctionentityTypes = getEntityTypesImpl(obj) entityType1 = obj.entityType('Wheel'); entityTypes = entityType1;endfunction[inputTypes,outputTypes] = getEntityPortsImpl(obj) inputTypes = {'Wheel'}; outputTypes={};endfunction[storageSpecs, I, O] = getEntityStorageImpl(obj) storageSpecs = obj.queuePriority('Wheel',obj.Capacity,'Diameter','ascending'); I = 1; O = [];endend%的实体进入事件actionmethodsfunction[entity, event] = WheelEntry(obj,storage,entity, source)% Entity entry invokes an iterate event.event = obj.eventIterate(1,'');end% itarate事件动作function[entity,event,next] = WheelIterate(obj,storage,entity,tag,cur)% Display wheel id, position in the storage, and diameter.coder.extrinsic('fprintf'); fprintf('Wheel id %d, Current position %d, Diameter %d\n',...entity.sys.id, cur.position, entity.data.Diameter);ifcur.size == cur.position fprintf('End of Iteration \n')endnext = true; event=[];endendend

Version History

Introduced in R2016a

See Also

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