class_docstr: Argument transform from (start, +-oo) to (0, 1)
class_docstr_tok: ["Argument","transform","from","(","start",",","+-oo",")","to","(","0",",","1",")"]
code: def __init__(self, func, start, infty):
      self._func = func
      self._start = start
      self._sgn = -1 if infty < 0 else 1
  
      # Overflow threshold for the 1/t**2 factor
      self._tmin = sys.float_info.min**0.5
  
imports: import sys
  import copy
  import heapq
  import collections
  import functools
  import numpy
  from scipy._lib._util import MapWrapper
label_desc: Use image node_id 1 to create a new SemiInfiniteFunc object  with example: obj = SemiInfiniteFunc(func, start, infty)