class_docstr: Statistical Power calculations for z-test for two independent samples.
  
  currently only uses pooled variance
class_docstr_tok: ["Statistical","Power","calculations","for","z-test","for","two","independent","samples",".","currently","only","uses","pooled","variance"]
code: def __init__(self, ddof=0, **kwds):
      self.ddof = ddof
      super().__init__(**kwds)
  
imports: import warnings
  import numpy
  from scipy import stats, optimize, special
  from statsmodels.tools.rootfinding import brentq_expanding
label_desc: Use image node_id 1 to create a new NormalIndPower object from inherited base classes: Power with example: obj = NormalIndPower(ddof)