class_docstr: Solve f(x, *args) == 0 using Algorithm748 of Alefeld, Potro & Shi.
      
class_docstr_tok: ["Solve","f","(","x",",","*","args",")","==","0","using","Algorithm748","of","Alefeld",",","Potro","&","Shi","."]
docstr: Call the user-supplied function, update book-keeping
docstr_tok: ["Call","the","user-supplied","function",",","update","book-keeping"]
code: def _callf(self, x, error=True):
      """Call the user-supplied function, update book-keeping"""
      fx = self.f(x, *self.args)
      self.function_calls += 1
      if not np.isfinite(fx) and error:
          raise ValueError(f"Invalid function value: f({x:f}) -> {fx} ")
      return fx
  
imports: import warnings
  from collections import namedtuple
  import operator
  from .None import _zeros
  from ._optimize import OptimizeResult, _call_callback_maybe_halt
  import numpy
label_desc: Use image node_id 3 for calling the TOMS748Solver obj's underlying member method code with example usage: obj._callf(x, error) and returns: fx