#!/usr/bin/env python
"""
This module defines the Frequency class and the TimeMethods Enum.
The Frequency class represents a frequency with a name, an approximate interval, and a time method.
The TimeMethods Enum represents various time methods declared in CMIP.
Examples
--------
Creating a Frequency instance:
>>> freq = Frequency("day", 1.0)
>>> print(freq.name)
day
>>> print(freq.approx_interval)
1.0
>>> print(freq.time_method)
TimeMethods.MEAN
Comparing two Frequency instances:
>>> freq1 = Frequency("day", 1.0)
>>> freq2 = Frequency("hr", 1.0/24)
>>> print(freq1 > freq2)
True
Getting a Frequency instance for a given name:
>>> freq = Frequency.for_name("day")
>>> print(freq.name)
day
"""
from enum import Enum
[docs]
class TimeMethods(Enum):
"""Various time methods declared in CMIP"""
MEAN = "MEAN"
INSTANTANEOUS = "INSTANTANEOUS"
CLIMATOLOGY = "CLIMATOLOGY"
NONE = "NONE"
CMIP_FREQUENCIES = {
"3hr": 3.0 / 24,
"6hrLev": 6.0 / 24,
"6hrPlev": 6.0 / 24,
"6hrPlevPt": 6.0 / 24,
"AERday": 1.0,
############################################################################################
# NOTE: for AERhr, data request 01.00.27 says "1.0" here, but this seems to be wrong
# NOTE: Taken from Jan Hegewald's seamore tool.
"AERhr": 1.0 / 24,
############################################################################################
"AERmon": 30.0,
"AERmonZ": 30.0,
"Amon": 30.0,
"CF3hr": 3.0 / 24,
"CFday": 1.0,
"CFmon": 30.0,
"day": 1.0,
"E3hr": 3.0 / 24,
"E3hrPt": 3.0 / 24,
"E6hrZ": 6.0 / 24,
"Eday": 1.0,
"EdayZ": 1.0,
"Emon": 30.0,
"EmonZ": 30.0,
"Eyr": 365.0,
"ImonAnt": 30.0,
"ImonGre": 30.0,
"IyrAnt": 365.0,
"IyrGre": 365.0,
"LImon": 30.0,
"Lmon": 30.0,
"Oclim": 30.0,
"Oday": 1.0,
"Odec": 3650.0,
"Omon": 30.0,
"Oyr": 365.0,
"SIday": 1.0,
"SImon": 30.0,
}
"""dict : A dictionary mapping CMIP6 frequency names to the number of days in that frequency."""
[docs]
class Frequency:
"""
Representation of a frequency.
Attributes
----------
name : str
The name of the frequency.
approx_interval : float
The approximate interval of the frequency.
time_method : TimeMethods
The time method of the frequency.
"""
def __init__(self, name, approx_interval, time_method=TimeMethods.MEAN):
self.name = name
self.approx_interval = approx_interval
self.time_method = time_method
def __eq__(self, other):
if isinstance(other, Frequency):
return self.name == other.name
return False
def __lt__(self, other):
return self.approx_interval < other.approx_interval
def __gt__(self, other):
return self.approx_interval > other.approx_interval
def __le__(self, other):
return self.approx_interval <= other.approx_interval
def __ge__(self, other):
return self.approx_interval >= other.approx_interval
[docs]
@classmethod
def for_name(cls, n):
"""
Get a Frequency instance for a given name.
Parameters
----------
n : str
The name of the frequency.
Returns
-------
Frequency
The Frequency instance for the given name.
Raises
------
ValueError
If no Frequency instance can be determined for the given name.
"""
freq = next((f for f in ALL if f.name == n), None)
if not freq:
raise ValueError(f"Cannot determine Frequency object for {n}")
return freq
# Defining the ALL list with Frequency instances
ALL = [
Frequency("1hr", 1.0 / 24),
Frequency("3hr", 3.0 / 24),
Frequency("6hr", 6.0 / 24),
Frequency("day", 1.0), # there is no dayPt frequency
Frequency("mon", 30.0),
Frequency("yr", 365.0),
Frequency("dec", 3650.0),
Frequency("1hrPt", 1.0 / 24, TimeMethods.INSTANTANEOUS),
Frequency("3hrPt", 3.0 / 24, TimeMethods.INSTANTANEOUS),
Frequency("6hrPt", 6.0 / 24, TimeMethods.INSTANTANEOUS),
Frequency("monPt", 30.0, TimeMethods.INSTANTANEOUS),
Frequency("yrPt", 365.0, TimeMethods.INSTANTANEOUS),
Frequency("1hrCM", 1.0 / 24, TimeMethods.CLIMATOLOGY),
Frequency("fx", 0, TimeMethods.NONE),
Frequency("monC", 30.0, TimeMethods.CLIMATOLOGY),
Frequency(
"subhrPt", 0.017361, TimeMethods.INSTANTANEOUS
), # there is no subhr time:mean
]
# Adding a global reference to ALL frequencies
# Frequency.ALL = ALL
