.ts File Format

This document formalises the .ts file format used by aeon. Encoded in utf-8, a .ts file stores a time-series dataset and its corresponding metadata (specified via string identifiers). String identifiers refer to strings beginning with @ in the file.

.ts files contains information blocks in the following order:

1. A description block. Contains any number of continuous lines starting with #. Each # is followed by an arbitrary (utf-8) sequence of symbols. The .ts specification does not prescribe any content for the description block, but it is common to include a description of the dataset contained in the file i.e. a full data dictionary, citations, etc.

2. A metadata block. Contains continuous lines starting with @. Each @ is directly followed a string identifier without whitespace (@<identifier>), followed by an appropriate value for the identifier where the value depends on type of identifier. There is no strict order of occurrence for all string identifiers, except @data which must be at the end of this block. The number of lines in this block depends on certain properties of the dataset (e.g: if the dataset is multivariate, an additional line is required to specify number of channels)

3. A dataset block. Contains a multiple collections of float values that represent the dataset. There are n cases each its own time series, delimited by new lines. The values for a series are expressed in a comma , seperated list and the index of each value is relative to its position in said list (0, 1, …, m). An instance may contain 1 to d channels, where each channel for a case is delimited using a colon :. In case timestamps are present, each value in a series is enclosed within round brackets i.e. (YYYY-MM-DD HH:mm:ss,<value>). The response variable is at the end of each case and is seperated via a colon.

Here is an extract from an examlple .ts file that shows portions of all three blocks:

#The data was generated from students wearing a smart watch.
#Consists of four classes, which are walking, resting, running and badminton.
...
@problemName BasicMotions
@timeStamps false
@missing false
...
@data
-0.740653,-0.740653,10.208449,2.867009:-0.194301,-0.194301,-0.249618,0.516079:Standing
-0.247409,-0.247409,-0.77129,-0.576154:-0.368484,-0.020851,-0.020851,-0.465607:Walking
...

For example files, see the files in aeon/datasets/data/ or the tsml Zenodo community.

Metadata

aeon’s core loader/writer functions relies on the existence of metadata to correctly load data into memory. It is also helpful to provide information about the dataset to a different user not familiar with the dataset.

The format of individual string identifier is: @<identifier> [value], except for @data where there is no trailing information. There should be a new line for each metadata entry.

Identifier	Description	Value	Additional Comments	Example
@problemname	The name of the dataset.	any string	Value cannot be space separated	BasicMotions
@timestamps	Whether timestamps are present.	true, false	true / false only	false
@missing	Whether there are missing values.	true, false	true / false only	false
@univariate	Whether there is only one dimension for the time series.	true, false	true / false only	false
@dimension	The number of channels.	integer > 0	Only present when @univariate false.	6
@equallength	Whether all cases are equal length.	true, false	true / false only	true
@serieslength	Number of timepoints in each case.	integer > 0	Only present if @equallength true.	100
@targetlabel	Whether there is a target label.	true, false	Exclusive to regression data; true / false only	true
@classlabel	Whether class labels are present.	false / true <string-1> <string-2> ..	Exclusive to classification data; when true, also contains space-seperated int/strings as labels.	true Standing Running Walking Badminton
@data	Marks the beginning of data.	-	The data begins from the next line.	-