Files

79 lines
2.6 KiB
Python

# -*- coding: utf-8 -*-
from pandas import DataFrame, Series
from pandas_ta._typing import DictLike, Int, IntFloat
from pandas_ta.utils import v_int, v_lowerbound, v_offset, v_series
def cube(
close: Series, pwr: IntFloat = None, signal_offset: Int = None,
offset: Int = None, **kwargs: DictLike
) -> DataFrame:
"""
Indicator: Cube Transform
John Ehlers describes this indicator to be useful in compressing signals
near zero for a normalized oscillator like the Inverse Fisher Transform.
In conjunction to that, values close to -1 and 1 are nearly unchanged,
whereas the ones near zero are reduced regarding their amplitude.
From the input data the effects of spectral dilation should have been
removed (i.e. roofing filter).
Sources:
Book: Cycle Analytics for Traders, 2014, written by John Ehlers
page 200
Coded by rengel8 based on Markus K. (cryptocoinserver)'s source.
Args:
close (pd.Series): Series of 'close's
pwr (float): Use this exponent 'wisely' to increase the impact of the
soft limiter. Default: 3
signal_offset (int): Offset the signal line. Default: -1
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.DataFrame: New feature generated.
"""
# Validate
close = v_series(close)
pwr = v_lowerbound(pwr, 3.0, 3.0, strict=False)
signal_offset = v_int(signal_offset, -1, 0)
offset = v_offset(offset)
# Calculate
result = close ** pwr
ct = Series(result, index=close.index)
ct_signal = Series(result, index=close.index)
# Offset
if offset != 0:
ct = ct.shift(offset)
ct_signal = ct_signal.shift(offset)
if signal_offset != 0:
ct = ct.shift(signal_offset)
ct_signal = ct_signal.shift(signal_offset)
# Fill
if "fillna" in kwargs:
ct.fillna(kwargs["fillna"], inplace=True)
ct_signal.fillna(kwargs["fillna"], inplace=True)
if "fill_method" in kwargs:
ct.fillna(method=kwargs["fill_method"], inplace=True)
ct_signal.fillna(method=kwargs["fill_method"], inplace=True)
# Name and Category
_props = f"_{pwr}_{signal_offset}"
ct.name = f"CUBE{_props}"
ct_signal.name = f"CUBEs{_props}"
ct.category = ct_signal.category = "transform"
df = DataFrame({ct.name: ct, ct_signal.name: ct_signal})
df.name = f"CUBE{_props}"
df.category = ct.category
return df