code: def CROTG(CA, CB, C=0, S=0):
      #     .. Scalar Arguments ..
      #      COMPLEX CA,CB,S
      #      REAL C
      #     ..
      #
      #  Purpose
      #  =======
      #
      #  CROTG determines a complex Givens rotation.
      #
      #  =====================================================================
      #
      #     .. Local Scalars ..
      #      COMPLEX ALPHA
      #      REAL NORM,SCALE
      #     ..
      if abs(CA) == 0.0:
          C = 0.0
          S = complex(1.0, 0.0)
          CA = CB
      else:
          SCALE = abs(CA) + abs(CB)
          NORM = SCALE * math.sqrt(
              (abs(CA / SCALE)) ** 2 + (abs(CB / SCALE)) ** 2
          )
          ALPHA = CA / abs(CA)
          C = abs(CA) / NORM
          S = ALPHA * (CB.conjugate()) / NORM
          CA = ALPHA * NORM
      return (CA, CB, C, S)
  
label_desc: Use image node_id 1 for calling a global function with example usage: CROTG(CA, CB, C, S) and returns: CA,  CB,  C,  S