BelAQI index

src/open_irceline/belaqi.py

@@ -0,0 +1,54 @@
+"""
+Compute the BelAQI index from concentrations of PM10, PM2.5, O3 and NO2, based on
+https://www.irceline.be/en/air-quality/measurements/belaqi-air-quality-index/information
+
+> to calculate the actual (hour per hour varying) sub-indexes and the global index, the concentration scales of Table 4
+> are applied to the latest hourly mean O3 and NO2 concentrations and the running 24-hourly mean PM2.5 and PM10
+> concentrations.
+"""
+from src.open_irceline.data import BelAqiIndex
+
+
+def belaqi_index(pm10: float, pm25: float, o3: float, no2: float) -> BelAqiIndex:
+    """
+    Computes the BelAQI index based on the components
+    Raise ValueError if a component is < 0
+    :param pm10: PM10 daily mean (or running 24-hourly mean for real-time) (µg/m³)
+    :param pm25: PM2.5 daily mean (or running 24-hourly mean for real-time) (µg/m³)
+    :param o3: O3 max 1-hourly mean per day (or latest hourly mean for real-time) (µg/m³)
+    :param no2: NO2 max 1-hourly mean per day (or latest hourly mean for real-time) (µg/m³)
+    :return: BelAQI index from 1 to 10 (Value of BelAqiIndex enum)
+    """
+
+    if pm10 < 0 or pm25 < 0 or o3 < 0 or no2 < 0:
+        raise ValueError("All the components should have a positive value")
+
+    elif pm10 > 100 or pm25 > 70 or o3 > 320 or no2 > 300:
+        return BelAqiIndex.HORRIBLE
+
+    elif pm10 > 80 or pm25 > 60 or o3 > 280 or no2 > 250:
+        return BelAqiIndex.VERY_BAD
+
+    elif pm10 > 70 or pm25 > 50 or o3 > 240 or no2 > 200:
+        return BelAqiIndex.BAD
+
+    elif pm10 > 60 or pm25 > 40 or o3 > 180 or no2 > 180:
+        return BelAqiIndex.VERY_POOR
+
+    elif pm10 > 50 or pm25 > 35 or o3 > 160 or no2 > 150:
+        return BelAqiIndex.POOR
+
+    elif pm10 > 40 or pm25 > 25 or o3 > 120 or no2 > 120:
+        return BelAqiIndex.MODERATE
+
+    elif pm10 > 30 or pm25 > 15 or o3 > 70 or no2 > 70:
+        return BelAqiIndex.FAIRLY_GOOD
+
+    elif pm10 > 20 or pm25 > 10 or o3 > 50 or no2 > 50:
+        return BelAqiIndex.GOOD
+
+    elif pm10 > 10 or pm25 > 5 or o3 > 25 or no2 > 20:
+        return BelAqiIndex.VERY_GOOD
+
+    elif pm10 >= 0 or pm25 >= 0 or o3 >= 0 or no2 >= 0:
+        return BelAqiIndex.EXCELLENT

src/open_irceline/data.py

@@ -1,5 +1,5 @@
 from datetime import datetime, date
-from enum import StrEnum
+from enum import StrEnum, Enum
 from typing import TypedDict
 
 
@@ -41,3 +41,16 @@ class FeatureValue(TypedDict):
     # Timestamp at which the value was computed
     timestamp: datetime | date
     value: int | float | None
+
+
+class BelAqiIndex(Enum):
+    EXCELLENT = 1
+    VERY_GOOD = 2
+    GOOD = 3
+    FAIRLY_GOOD = 4
+    MODERATE = 5
+    POOR = 6
+    VERY_POOR = 7
+    BAD = 8
+    VERY_BAD = 9
+    HORRIBLE = 10

tests/test_belaqi.py

@@ -0,0 +1,54 @@
+from src.open_irceline.belaqi import belaqi_index
+from src.open_irceline.data import BelAqiIndex
+
+
+def test_belaqi_index():
+    # Excellent
+    assert belaqi_index(5, 2, 10, 10) == BelAqiIndex.EXCELLENT
+    assert belaqi_index(0, 0, 0, 0) == BelAqiIndex.EXCELLENT
+    assert belaqi_index(10, 5, 25, 20) == BelAqiIndex.EXCELLENT
+
+    # Very good
+    assert belaqi_index(15, 8, 40, 35) == BelAqiIndex.VERY_GOOD
+    assert belaqi_index(11, 6, 26, 21) == BelAqiIndex.VERY_GOOD
+    assert belaqi_index(20, 10, 50, 50) == BelAqiIndex.VERY_GOOD
+
+    # Good
+    assert belaqi_index(25, 12, 60, 60) == BelAqiIndex.GOOD
+    assert belaqi_index(21, 11, 51, 51) == BelAqiIndex.GOOD
+    assert belaqi_index(30, 15, 70, 70) == BelAqiIndex.GOOD
+
+    # Fairly good
+    assert belaqi_index(35, 20, 100, 90) == BelAqiIndex.FAIRLY_GOOD
+    assert belaqi_index(31, 16, 71, 71) == BelAqiIndex.FAIRLY_GOOD
+    assert belaqi_index(40, 25, 120, 120) == BelAqiIndex.FAIRLY_GOOD
+
+    # Moderate
+    assert belaqi_index(45, 30, 140, 130) == BelAqiIndex.MODERATE
+    assert belaqi_index(41, 26, 121, 121) == BelAqiIndex.MODERATE
+    assert belaqi_index(50, 35, 160, 150) == BelAqiIndex.MODERATE
+
+    # Poor
+    assert belaqi_index(55, 38, 170, 160) == BelAqiIndex.POOR
+    assert belaqi_index(51, 36, 161, 151) == BelAqiIndex.POOR
+    assert belaqi_index(60, 40, 180, 180) == BelAqiIndex.POOR
+
+    # Very poor
+    assert belaqi_index(65, 45, 200, 190) == BelAqiIndex.VERY_POOR
+    assert belaqi_index(61, 41, 181, 181) == BelAqiIndex.VERY_POOR
+    assert belaqi_index(70, 50, 240, 200) == BelAqiIndex.VERY_POOR
+
+    # Bad
+    assert belaqi_index(75, 55, 260, 220) == BelAqiIndex.BAD
+    assert belaqi_index(71, 51, 241, 201) == BelAqiIndex.BAD
+    assert belaqi_index(80, 60, 280, 250) == BelAqiIndex.BAD
+
+    # Very bad
+    assert belaqi_index(85, 65, 300, 270) == BelAqiIndex.VERY_BAD
+    assert belaqi_index(81, 61, 281, 251) == BelAqiIndex.VERY_BAD
+    assert belaqi_index(100, 70, 320, 300) == BelAqiIndex.VERY_BAD
+
+    # Horrible
+    assert belaqi_index(110, 75, 330, 310) == BelAqiIndex.HORRIBLE
+    assert belaqi_index(101, 71, 321, 301) == BelAqiIndex.HORRIBLE
+    assert belaqi_index(150, 100, 400, 400) == BelAqiIndex.HORRIBLE