#moonaqi

#Quick start

///|
let table = @moonaqi.hj633_2026(@moonaqi.Pm25, @moonaqi.Daily).unwrap()
let sub = @moonaqi.iaqi(table, 60.0)          // Some(100)

///|
let readings = [
  @moonaqi.Reading::of(@moonaqi.Pm25, @moonaqi.Daily, 60.0),
  @moonaqi.Reading::of(@moonaqi.No2, @moonaqi.Daily, 40.0),
]
let air = @moonaqi.aqi(readings).unwrap()
air.index()             // 100
air.category().name()   // "Good"
air.dominant()          // [Pm25]

#Interpolation

IAQI = (I_high - I_low) / (C_high - C_low) * (C - C_low) + I_low

///|
let iaqi = @moonaqi.iaqi(
  [
    @moonaqi.Breakpoint::new(0.0, 35.0, 0, 50),
    @moonaqi.Breakpoint::new(35.0, 75.0, 50, 100),
    @moonaqi.Breakpoint::new(75.0, 115.0, 100, 150),
  ],
  55.0,
)

#The standard's tables

#The index

///|
let air = @moonaqi.aqi([
  @moonaqi.Reading::of(@moonaqi.Pm25, @moonaqi.Daily, 60.0),
  @moonaqi.Reading::of(@moonaqi.No2, @moonaqi.Daily, 40.0),
]).unwrap()

#The EPA's tables

///|
let air = @moonaqi.aqi_with(@moonaqi.Epa, [
  @moonaqi.Reading::new(@moonaqi.Pm25, @moonaqi.Daily, 20.0),
  @moonaqi.Reading::new(@moonaqi.O3, @moonaqi.EightHour, 0.07),
]).unwrap()

#NowCast

///|
let nowcast = @moonaqi.nowcast_pm25([Some(30.0), Some(20.0), Some(10.0)])

#A day of hours

///|
let day = @moonaqi.Day::new("STATION")

///|
// One pass per hour, recording every pollutant, so that gaps in one series
// cannot shift another's hours.
for hour = 0; hour < 24; hour = hour + 1 {
  day.record(@moonaqi.Pm25, Some(35.0))
  day.record(@moonaqi.O3, Some(if hour < 12 { 100.0 } else { 160.0 }))
}

///|
let rules = @moonaqi.DayRules::new(
  @moonaqi.Window::new(24, 20), // a day over 24 hours, at least 20 reported
  @moonaqi.Window::new(8, 6),   // ozone over its highest 8, at least 6
)

///|
day.aqi(@moonaqi.China, rules).unwrap()

• A missing hour is not a nought. An average is taken over the hours that carry a reading, so a monitor that was down for an hour does not drag the day towards a number nobody measured.
• Ozone is its highest eight-hour average, not its daily average. The window slides, so the worst stretch can straddle any boundary; on a day of twelve hours at 100 and twelve at 160, the whole-day average is 130 and the answer is 160.
• An indicator too thin to average is left out. The standards call that a missing indicator, and it is reported as one rather than guessed at.

#A period

///|
let summary = @moonaqi.Summary::new()

///|
summary.add("STATION A", day.aqi(@moonaqi.China, rules).unwrap())

///|
summary.days()          // days counted
summary.good_days()     // index at or below 100
summary.heavy_days()    // index above 200
summary.good_rate()     // the share of the period, as a fraction of one
summary.worst_index()   // and the station it came from
summary.most_frequent_primary()

#Bands

#Demo

$ moon run cmd/main
daily report (日报)

  pollutant  concentration   IAQI
  PM2.5      115 ug/m3       150
  PM10       120 ug/m3       100
  SO2        50 ug/m3        50
  NO2        40 ug/m3        50
  CO         4 mg/m3         100
  O3         160 ug/m3       100

  AQI 150   Lightly polluted / 轻度污染
  primary pollutant   PM2.5
  over the limit      PM2.5

$ moon run cmd/main -- --station STATION \
    --series PM2.5=35x24 --series NO2=,40x23 --series O3=100x12,160x12
moonaqi — a day of hours, averaged and indexed

  station   STATION (HJ 633—2026)
  rules     a day over 24 hours with at least 20 reported, ozone over its highest 8 with at least 6

  PM2.5   24 hours, 24 reported   24-hour average   35 ug/m3
  NO2     24 hours, 23 reported   24-hour average   40 ug/m3
  O3      24 hours, 24 reported   8-hour maximum    160 ug/m3

  AQI 100   Good / 良   Yellow / 黄色
  primary pollutant   O3

$ moon run cmd/main -- --json
{
  "report": "daily",
  "aqi": 150,
  "category": "Lightly polluted",
  "chinese_category": "轻度污染",
  ...
}

#Sources

#Testing

moon test

#Licence