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Python

# -*- coding: utf-8 -*-
from pandas import Series
from pandas_ta._typing import DictLike, Int, IntFloat
from pandas_ta.ma import ma
from pandas_ta.utils import v_mamode, v_offset, v_pos_default, v_series
# - Standard definition of your custom indicator function (including docs)-
def ni(
close: Series, length: Int = None,
centered: bool = False, mamode: str = None,
offset: Int = None, **kwargs: DictLike
):
"""Example indicator (NI)
Is an indicator provided solely as an example
Sources:
https://github.com/twopirllc/pandas-ta/issues/264
Calculation:
Default Inputs:
length=20, centered=False
SMA = Simple Moving Average
t = int(0.5 * length) + 1
ni = close.shift(t) - SMA(close, length)
if centered:
ni = ni.shift(-t)
Args:
close (pd.Series): Series of 'close's
length (int): It's period. Default: 20
mamode (str): Chosen Moving Average. Default: "sma"
centered (bool): Shift the ni back by int(0.5 * length) + 1. Default: False
offset (int): How many periods to offset the result. Default: 0
Kwargs:
fillna (value, optional): pd.DataFrame.fillna(value)
fill_method (value, optional): Type of fill method
Returns:
pd.Series: New feature generated.
""" # Validate Arguments
length = v_pos_default(length, 20)
close = v_series(close, length)
if close is None:
return
mamode = v_mamode(mamode, "sma")
offset = v_offset(offset)
# Calculate Result
ma = ma(mamode, close, length=length, **kwargs)
t = int(0.5 * length) + 1
ni = close - ma.shift(t)
if centered:
ni = (close.shift(t) - ma).shift(-t)
# Offset
if offset != 0:
ni = ni.shift(offset)
# Handle fills
if "fillna" in kwargs:
ni.fillna(kwargs["fillna"], inplace=True)
if "fill_method" in kwargs:
ni.fillna(method=kwargs["fill_method"], inplace=True)
# Name and Categorize it
ni.name = f"ni_{length}"
ni.category = "trend"
return ni
# - Define a matching class method --------------------------------------------
def ni_method(self, length=None, offset=None, **kwargs):
close = self._get_column(kwargs.pop("close", "close"))
result = ni(close=close, length=length, offset=offset, **kwargs)
return self._post_process(result, **kwargs)