ps2d.py 文件源码

def calc_ps3d(self):
        """
        Calculate the 3D power spectrum of the image cube.

        The power spectrum is properly normalized to have dimension
        of [K^2 Mpc^3].
        """
        if self.window is not None:
            logger.info("Applying window along frequency axis ...")
            self.cube *= self.window[:, np.newaxis, np.newaxis]

        logger.info("3D FFTing data cube ...")
        cubefft = fftpack.fftshift(fftpack.fftn(self.cube))

        logger.info("Calculating 3D power spectrum ...")
        ps3d = np.abs(cubefft) ** 2  # [K^2]
        # Normalization
        norm1 = 1 / (self.Nx * self.Ny * self.Nz)
        norm2 = 1 / (self.fs_xy**2 * self.fs_z)  # [Mpc^3]
        norm3 = 1 / (2*np.pi)**3
        self.ps3d = ps3d * norm1 * norm2 * norm3  # [K^2 Mpc^3]
        return self.ps3d