Max 1-Day Precipitation RX1day Extractor
Extract observed RX1day with all tied ordinal indices and first maximum, without inventing a date for an incomplete series.
Description
Maximum one-day precipitation identifies the largest observed daily rainfall in a supplied period.
Maximum one-day precipitation identifies the largest observed daily rainfall in a supplied period. Retaining every tied day makes repeated extremes visible rather than selecting just one record.1, 2
Extract observed RX1day with all tied ordinal indices and first maximum, without inventing a date for an incomplete series.
When to use Max 1-Day Precipitation RX1day Extractor
Use this tool to extract observed RX1day with all tied ordinal indices and first maximum, without inventing a date for an incomplete series.
Prepare the climate observations and any independently chosen thresholds or model parameters. Confirm units, daily coverage, time order and the intended seasonal window.
How to use Max 1-Day Precipitation RX1day Extractor and understand its results
- Prepare the climate observations and any independently chosen thresholds or model parameters. Confirm units, daily coverage, time order and the intended seasonal window.
- Enter dailyPrecipitationMm using the field table and calculation rules, then run the tool.
- Read rx1dayMm, firstMaximumDayIndex, tiedMaximumDayIndices. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| dailyPrecipitationMm | Daily precipitation mm | list of number | Required |
Enter a nonempty list of nonnegative daily precipitation in mm. The tool finds the maximum and all zero-based indices exactly equal to it, and returns the first such index separately. An all-zero series is valid and every day is tied for the maximum.
Rx1day = max P_i; tied indices = {i : P_i = Rx1day} Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| rx1dayMm | Rx1day mm | number |
| firstMaximumDayIndex | First maximum day index | number |
| tiedMaximumDayIndices | Tied maximum day indices | list of number |
{
"input": {
"dailyPrecipitationMm": [
1,
5,
5,
2
]
},
"output": {
"rx1dayMm": 5,
"firstMaximumDayIndex": 1,
"tiedMaximumDayIndices": [
1,
2
]
}
}Limitations and assumptions
The tool does not choose an annual period, attach calendar dates, resolve accumulation-time differences or infer a return period. Exact equality controls ties; measurement rounding can therefore create several tied records.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Max 5-Day Precipitation RX5day Extractor: Extract RX5day from all complete overlapping five-day windows in a gap-free sequence, permitting cross-month windows supplied by caller; not monthly totals or partial-window extrapolation. For a complementary task, use Rainy Days Threshold Counter: Audit a supplied increasing rain-threshold policy over observed daily precipitation with coverage denominator; no missing-as-dry treatment or climate category lookup.
Further background: Climate extreme index definitions.
References
-
Max 1-Day Precipitation RX1day Extractor — tool.io
-
Climate extreme index definitions — Climdex
Similar or alternative tools
- Max 5-Day Precipitation RX5day Extractor
Extract RX5day from all complete overlapping five-day windows in a gap-free sequence, permitting cross-month windows supplied by caller; not monthly totals or partial-window extrapolation.
- Rainy Days Threshold Counter
Audit a supplied increasing rain-threshold policy over observed daily precipitation with coverage denominator; no missing-as-dry treatment or climate category lookup.