lisbon_air_quality.int: Lisbon Air Quality Daily Interval Dataset

In dataSDA: Datasets and Basic Statistics for Symbolic Data Analysis

Lisbon Air Quality Daily Interval Dataset

Description

Interval-valued daily air quality data from the Entrecampos monitoring station in Lisbon, Portugal, covering 2019–2021 (1096 days). Each day's pollutant concentration is represented as a [\min, \max] interval from hourly measurements. Missing days are imputed via linear interpolation.

Usage

data(lisbon_air_quality.int)

Format

A symbolic data frame (symbolic_tbl) with 1096 observations (daily) and 8 interval-valued pollutant variables:

• so2: Sulphur dioxide (ug/m3).

• pm10: Particulate matter < 10 um (ug/m3).

• o3: Ozone (ug/m3).

• no2: Nitrogen dioxide (ug/m3).

• co: Carbon monoxide (ug/m3).

• pm25: Particulate matter < 2.5 um (ug/m3).

• nox: Nitrogen oxides (ug/m3).

• no: Nitric oxide (ug/m3).

Metadata

Sample size (n)	1096
Variables (p)	8
Subject area	Environment
Symbolic format	Interval
Analytical tasks	Regression, Time series

Source

QualAr, Entrecampos station, Lisbon, Portugal.

References

Dias, S. and Brito, P. (2017). Off the beaten track: A new linear model for interval data. European Journal of Operational Research, 258(3), 1118–1130.

Data from the QualAr Portuguese air quality monitoring network (‘⁠https://qualar.apambiente.pt/⁠’).

Examples

data(lisbon_air_quality.int)

dataSDA documentation built on June 12, 2026, 9:06 a.m.