SolarNetwork Core

Class: StreamAggregateDatum

domain~ StreamAggregateDatum

A stream aggregate datum entity.

A stream aggregate datum is a datum representing some aggregate calculation, without any metadata describing the datum property names. The instantantaneous and accumulating property values are stored as 2D array fields iProps and aProps that hold the property values as well as associated aggregate statistics. The datum status properties are stroed in the 1D array field sProps. A DatumStreamMetadata object is required to associate names with these arrays.

The instantaneous properties are 4-element arrays containing:

  1. property average value
  2. property count
  3. minimum value
  4. maximum value

The accumulatingn statistics are 3-element arrays containing:

  1. difference between ending and starting property values
  2. starting property value
  3. ending property value

new StreamAggregateDatum(streamId, ts [, iProps] [, aProps] [, sProps] [, tags])

Constructor.

Parameters:
Name Type Argument Description
streamId string

the datum stream ID
ts Array.<(Date|number|string)>

an array with 2 elements for the datum start and end timestamps, either as a Date instance or a form suitable for constructing as new Date(ts)
iProps Array.<Array.<number>> <optional>

the instantaneous property values and associated statistics
aProps Array.<Array.<number>> <optional>

the accumulating property values and associated statistics
sProps Array.<String> <optional>

the status property values
tags Set.<String> | Array.<String> <optional>

the tag values

Methods

<static> fromJsonEncoding(json, meta)

Parse a JSON string into a StreamAggregateDatum instance.

The JSON must be encoded the same way StreamAggregateDatum#toJsonEncoding() does.

Parameters:
Name Type Description
json string

the JSON to parse
meta module:domain~DatumStreamMetadata | module:util~DatumStreamMetadataRegistry

a metadata instance or metadata registry to decode with
Returns:

the stream datum instance

Type
module:domain~StreamAggregateDatum

<static> fromJsonObject(data, meta)

Create a new StreamAggregateDatum instance from an array parsed from a stream datum JSON string.

The array must have been parsed from JSON that was encoded the same way StreamAggregateDatum#toJsonEncoding() does.

Parameters:
Name Type Description
data Array

the array parsed from JSON
meta module:domain~DatumStreamMetadata | module:util~DatumStreamMetadataRegistry

a metadata instance or metadata registry to decode with
Returns:

the stream datum instance

Type
module:domain~StreamAggregateDatum

toJsonEncoding( [registry])

Get this object as a standard JSON encoded string value.

This method returns the JSON form of the result of StreamAggregateDatum#toJsonObject().

Parameters:
Name Type Argument Description
registry module:util~DatumStreamMetadataRegistry <optional>

a stream metadata registry to encode as a registry-indexed stream datum
Returns:

the JSON encoded string

Type
string

toJsonObject( [registry])

Get this object as an array suitable for encoding into a standard stream datum JSON string.

This method can encode the datum into an array using one of two ways, depending on whether the registry argument is provided. When provided, the first array element will be the stream metadata index based on calling DatumStreamMetadataRegistry#indexOfMetadataStreamId(). Otherwise the first array element will be the stream ID itself.

For example if a registry is used, the resulting array might look like this:

[0,[1650945600000,1651032000000],[3.6,2,0,7.2],[19.1,2,18.1, 20.1],[1.422802,1138.446687,1139.869489]]

while without a registry the array might look like this:

["7714f762-2361-4ec2-98ab-7e96807b32a6", [1650945600000,1651032000000],[3.6,2,0,7.2],[19.1,2,18.1, 20.1],[1.422802,1138.446687,1139.869489]]
Parameters:
Name Type Argument Description
registry module:util~DatumStreamMetadataRegistry <optional>

a stream metadata registry to encode as a registry-indexed stream datum
Returns:

the datum stream array object

Type
Array

toObject(meta [, withoutStatistics])

Get this instance as a simple object.

The following basic properties will be set on the returned object:

  • streamId - the stream ID
  • date - the timestamp
  • date_end - the ending timestamp, if available
  • sourceId - the metadata source ID
  • nodeId or locationId - either the node ID or location ID from the metadata
  • tags - any tags (as an Array)

Beyond that, all instantaneous, accumulating, and status properties will be included. If duplicate property names exist between the different classifications, the first-available value will be used. Any available statistics for each property are included as well, using property names with the following suffixes:

  • _count - count of datum
  • _min - minimum value
  • _max - maximum value
  • _start - starting value
  • _end - ending value
Parameters:
Name Type Argument Description
meta module:domain~DatumStreamMetadata

a metadata instance to encode the property names with
withoutStatistics boolean <optional>

{@literal true} to omit statistic properties
Returns:

an object populated with all available properties

Type
Object