code: def nanmin(a, axis=None, out=None, keepdims=False):
      """Returns the minimum of an array along an axis ignoring NaN.
  
      When there is a slice whose elements are all NaN, a :class:`RuntimeWarning`
      is raised and NaN is returned.
  
      Args:
          a (cupy.ndarray): Array to take the minimum.
          axis (int): Along which axis to take the minimum. The flattened array
              is used by default.
          out (cupy.ndarray): Output array.
          keepdims (bool): If ``True``, the axis is remained as an axis of
              size one.
  
      Returns:
          cupy.ndarray: The minimum of ``a``, along the axis if specified.
  
      .. warning::
  
          This function may synchronize the device.
  
      .. seealso:: :func:`numpy.nanmin`
  
      """
      # TODO(niboshi): Avoid synchronization.
      res = _core.nanmin(a, axis=axis, out=out, keepdims=keepdims)
      if content.isnan(res).any():  # synchronize!
          warnings.warn("All-NaN slice encountered", RuntimeWarning)
      return res
  
file_path: cupy/cupy/_statistics/order.py
imports: import warnings
  import cupy
  from cupy import _core
  from cupy._core import _routines_statistics
  from cupy._core import _fusion_thread_local
  from cupy._logic import content
label_desc: Use image node_id 3 for calling a global function with example usage: nanmin(a, axis, out, keepdims) and returns: res