code: def erf(x, out=None, where=None, **kwargs):
      """
      Returns the error function of complex argument.
  
      It is defined as ``2/sqrt(pi)*integral(exp(-t**2), t=0..z)``.
  
      Parameters
      ----------
      x : Tensor
          Input tensor.
  
      Returns
      -------
      res : Tensor
          The values of the error function at the given points `x`.
  
      See Also
      --------
      erfc, erfinv, erfcinv, wofz, erfcx, erfi
  
      Notes
      -----
      The cumulative of the unit normal distribution is given by
      ``Phi(z) = 1/2[1 + erf(z/sqrt(2))]``.
  
      References
      ----------
      .. [1] https://en.wikipedia.org/wiki/Error_function
      .. [2] Milton Abramowitz and Irene A. Stegun, eds.
          Handbook of Mathematical Functions with Formulas,
          Graphs, and Mathematical Tables. New York: Dover,
          1972. http://www.math.sfu.ca/~cbm/aands/page_297.htm
      .. [3] Steven G. Johnson, Faddeeva W function implementation.
         http://ab-initio.mit.edu/Faddeeva
  
      Examples
      --------
      >>> import mars.tensor as mt
      >>> from mars.tensor import special
      >>> import matplotlib.pyplot as plt
      >>> x = mt.linspace(-3, 3)
      >>> plt.plot(x, special.erf(x))
      >>> plt.xlabel('$x$')
      >>> plt.ylabel('$erf(x)$')
      >>> plt.show()
      """
      op = TensorErf(**kwargs)
      return op(x, out=out, where=where)
  
imports: import scipy.special
  from ..arithmetic.utils import arithmetic_operand
  from ..utils import infer_dtype, implement_scipy
  from .core import TensorSpecialUnaryOp, TensorSpecialMultiOp, TensorTupleOp, _register_special_op
label_desc: Use image node_id 1 for calling a global function with example usage: erf(x, out, where) and returns: op