Nodal Demand Functions

These functions are used for managing nodal demands.

Function	Description
`addDemand`	appends a new demand to a junction node demands list.
`deleteDemand`	deletes a demand from a junction node.
`getBaseDemand`	Gets the base demand for one of a node’s demand categories.
`getDemandIndex`	Retrieves the index of a node’s named demand category.
`getDemandModel`	Retrieves the type of demand model in use and its parameters.
`getDemandName`	Retrieves the name of a node’s demand category.
`getDemandPattern`	Retrieves the index of a time pattern assigned to one of a node’s demand categories.
`getNumberOfDemands`	Retrieves the number of demand categories for a junction node.
`setBaseDemand`	Sets the base demand for one of a node’s demand categories.
`setDemandModel`	Sets the type of demand model to use and its parameters.
`setDemandName`	Assigns a name to a node’s demand category.
`setDemandPattern`	Sets the index of a time pattern used for one of a node’s demand categories.

addDemand

appends a new demand to a junction node demands list.

addDemand(nodeIndex: number, baseDemand: number, demandPattern: string, demandName: string): void;

Parameters

Parameter	Type	Description
nodeIndex	`number`	the index of a node (starting from 1).
baseDemand	`number`	the demand’s base value.
demandPattern	`string`	the name of a time pattern used by the demand
demandName	`string`	the name of the demand’s category

A NULL or blank string can be used for demandPattern and for demandName to indicate that no time pattern or category name is associated with the demand.

deleteDemand

Deletes a demand from a junction node.

deleteDemand(nodeIndex: number, demandIndex: number): void;

Parameters

Parameter	Type	Description
nodeIndex		the index of a node (starting from 1).
demandIndex		the position of the demand in the node’s demands list (starting from 1).

getBaseDemand

Gets the base demand for one of a node’s demand categories.

getBaseDemand(nodeIndex: number, demandIndex: number): number;

Parameters

Parameter	Type	Description
nodeIndex	`number`	a node’s index (starting from 1).
demandIndex	`number`	the index of a demand category for the node (starting from 1).

Returns

Number the category’s base demand.

getDemandIndex

Retrieves the index of a node’s named demand category.

getDemandIndex(nodeIndex: number, demandName: string): number;

Parameters

Parameter	Type	Description
nodeIndex	`number`	the index of a node (starting from 1)
demandName	`string`	the name of a demand category for the node

Returns

Number the index of the demand being sought

getDemandModel

Retrieves the type of demand model in use and its parameters.

getDemandModel(): {
type: DemandModel;
pmin: number;
preq: number;
pexp: number;
};

Returns

Object

{
  type: DemandModel;
  pmin: number;
  preq: number;
  pexp: number;
}

Property	Type	Description
type	`DemandModel`	Type of demand model (see `DemandModel`).
pmin	`number`	Pressure below which there is no demand.
preq	`number`	Pressure required to deliver full demand.
pexp	`number`	Pressure exponent in demand function.

Parameters pmin, preq, and pexp are only used when the demand model is DemandModel.PDA.

getDemandName

Retrieves the name of a node’s demand category.

getDemandName(nodeIndex: number, demandIndex: number): string;

Parameters

Parameter	Type	Description
nodeIndex	`number`	a node’s index (starting from 1).
demandIndex	`number`	the index of one of the node’s demand categories (starting from 1).

Returns

String The name of the selected category.

getDemandPattern

Retrieves the index of a time pattern assigned to one of a node’s demand categories.

getDemandPattern(nodeIndex: number, demandIndex: number): number;

Parameters

Parameter	Type	Description
nodeIndex	`number`	the node’s index (starting from 1).
demandIndex	`number`	the index of a demand category for the node (starting from 1).

Returns

Number the index of the category’s time pattern.

A returned pattern index of 0 indicates that no time pattern has been assigned to the demand category.

getNumberOfDemands

Retrieves the number of demand categories for a junction node.

getNumberOfDemands(nodeIndex: number): number;

Parameters

Parameter	Type	Description
nodeIndex	`number`	the index of a node (starting from 1).

Returns

Number the number of demand categories assigned to the node.

setBaseDemand

Sets the base demand for one of a node’s demand categories.

setBaseDemand(nodeIndex: number, demandIndex: number, baseDemand: number): void;

Parameters

Parameter	Type	Description
nodeIndex	`number`	a node’s index (starting from 1).
demandIndex	`number`	the index of a demand category for the node (starting from 1).
baseDemand	`number`	the new base demand for the category.

setDemandModel

Sets the type of demand model to use and its parameters.

setDemandModel(type: DemandModel, pmin: number, preq: number, pexp: number): void;

Parameters

Parameter	Type	Description
type	`DemandModel`	Type of demand model (see `DemandModel`).
pmin	`number`	Pressure below which there is no demand.
preq	`number`	Pressure required to deliver full demand.
pexp	`number`	Pressure exponent in demand function.

Set type to EN_DDA for a traditional demand driven analysis (in which case the remaining three parameter values are ignored) or to EN_PDA for a pressure driven analysis. In the latter case a node’s demand is computed as:

Dfull * [ (P - pmin) / (preq - pmin) ] ^ pexp

where Dfull is the full demand and P is the current pressure.

Setting preq equal to pmin will result in a solution with the smallest amount of demand reductions needed to insure that no node delivers positive demand at a pressure below pmin.

setDemandName

Assigns a name to a node’s demand category.

setDemandName(nodeIndex: number, demandIdx: number, demandName: string): void;

Parameters

Parameter	Type	Description
nodeIndex	`number`	a node’s index (starting from 1).
demandIdx	`number`	the index of one of the node’s demand categories (starting from 1).
demandName	`string`	the new name assigned to the category.

setDemandPattern

Sets the index of a time pattern used for one of a node’s demand categories.

setDemandPattern(nodeIndex: number, demandIndex: number, patIndex: number): void;

Parameters

Parameter	Type	Description
nodeIndex	`number`	a node’s index (starting from 1).
demandIndex	`number`	the index of one of the node’s demand categories (starting from 1).
patIndex	`number`	the index of the time pattern assigned to the category.

Specifying a pattern index of 0 indicates that no time pattern is assigned to the demand category.