Nodal Demand Functions

These functions are used for managing nodal demands.

Function	Versions	Description
addDemand	2.2+	Appends a new demand to a junction node demands list.
deleteDemand	2.2+	Deletes a demand from a junction node.
getBaseDemand	2.2+	Gets the base demand for one of a node’s demand categories.
getDemandIndex	2.2+	Retrieves the index of a node’s named demand category.
getDemandModel	2.2+	Retrieves the type of demand model in use and its parameters.
getDemandName	2.2+	Retrieves the name of a node’s demand category.
getDemandPattern	2.2+	Retrieves the index of a time pattern assigned to one of a node’s demand categories.
getNumberOfDemands	2.2+	Retrieves the number of demand categories for a junction node.
setBaseDemand	2.2+	Sets the base demand for one of a node’s demand categories.
setDemandModel	2.2+	Sets the type of demand model to use and its parameters.
setDemandName	2.2+	Assigns a name to a node’s demand category.
setDemandPattern	2.2+	Sets the index of a time pattern used for one of a node’s demand categories.

---

addDemand 2.2+

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 2.2+

Deletes a demand from a junction node.

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

Parameters

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

---

getBaseDemand 2.2+

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 2.2+

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 2.2+

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 2.2+

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 2.2+

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 2.2+

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 2.2+

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 2.2+

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 2.2+

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 2.2+

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.