Multiple Timeseries

A timeseries represents an ordered collection of values of an event (or item) over time. A multiple timeseries represents the collection of multiple timeseries gathered from multiple items over a particular duration. Depending on the values stored in a series, a multiple timeseries can be broadly classified into two types:

  • Binary multiple timeseries and

  • (non-binary) multiple timeseries .

Binary Multiple Timeseries

A binary multiple time series represents the binary data of multiple items split into temporal windows. An example of this series is shown below.

windowID

binary sequences

1

(a,1) (a,3) (b,2) (b,3) (c,2) (c,3)

2

(a,1) (b,1) (b,2) (b,3) (c,1)

3

(a,1) (a,2) (b,1) (b,3) (c,2)

4

(a,1) (b,1) (b,2) (c,3)

5

(a,1) (a,3) (b,3) (c,2) (c,2)

6

(a,1) (a,2) (b,2) (b,3)

Rules to create a binary multiple time series.

  • First column must contain an integer representing an windowID.

  • Remaining columns must contain items and their timestamps within braces.

  • In the braces, starting from left hand side, the first word/letter represents an item and the other word/letter represents an timestamp.

  • Columns are seperated with a seperator.

  • ‘ Tab space ’ is the default seperator. However, transactional databases can be constructed using other seperators, such as comma and space.

Format of a binary multiple time series:

>>>  windowID<sep>(item,timestamp)<sep>(item,timestamp)<sep>...<sep>(item, timestamp)

An example

1

(a,1) (a,3) (b,2) (b,3) (c,2) (c,3)

2

(a,1) (b,1) (b,2) (b,3) (c,1)

3

(a,1) (a,2) (b,1) (b,3) (c,2)

4

(a,1) (b,1) (b,2) (c,3)

5

(a,1) (a,3) (b,3) (c,2) (c,2)

6

(a,1) (a,2) (b,2) (b,3)