code: def get_factors(self, unique_R, inds, centers, widths):
          
  
          F = np.zeros((len(inds[0]), self.K))
          tfa_extension.factor(
              F,
              centers,
              widths,
              unique_R[0],
              unique_R[1],
              unique_R[2],
              inds[0],
              inds[1],
              inds[2])
  
          return F
docs: Calculate factors based on centers and widths
  
          Parameters
          ----------
  
          unique_R : a list of array,
              Each element contains unique value in one dimension of
              scanner coordinate matrix R.
  
          inds : a list of array,
              Each element contains the indices to reconstruct one
              dimension of original cooridnate matrix from the unique
              array.
  
          centers : 2D array, with shape [K, n_dim]
              The centers of  factors.
  
          widths : 1D array, with shape [K, 1]
              The widths of factors.
  
  
          Returns
          -------
  
          F : 2D array, with shape [n_voxel,self.K]
              The latent factors from fMRI data.