import numpy as np
from .catch_errors import check_for_period_error
from .function_helper import fill_for_noncomputable_vals
np.seterr(divide='ignore', invalid='ignore')
def standard_variance(data, period):
"""
Standard Variance.
Formula:
(Ct - AVGt)^2 / N
"""
check_for_period_error(data, period)
sv = list(map(
lambda idx:
np.var(data[idx+1-period:idx+1], ddof=1),
range(period-1, len(data))
))
sv = fill_for_noncomputable_vals(data, sv)
return sv