code: def _polyval(p, x):
      p = cupy.asarray(p)
      x = cupy.asanyarray(x)
      y = cupy.zeros_like(x)
      for pv in p:
          y = y * x + pv
      return y
  
file_path: cupy/cupyx/scipy/signal/_savitzky_golay.py
imports: import math
  import cupy
  from cupy.linalg import lstsq
  from cupyx.scipy.ndimage import convolve1d
  from ._arraytools import axis_slice
label_desc: Use image node_id 2 for calling a global function with example usage: _polyval(p, x) and returns: y