code: def spdar1(ar, w):
      if np.ndim(ar) == 0:
          rho = ar
      else:
          rho = -ar[1]
      return 0.5 / np.pi / (1 + rho * rho - 2 * rho * np.cos(w))
  
imports: import numpy
  import numpy.fft
  from scipy import signal
  from statsmodels.tsa.arima_process import ArmaProcess
label_desc: Use image node_id 1 for calling a global function with example usage: spdar1(ar, w) and returns: unknown