fix(cross): compute total squared covariance in PC space (#221)

xeofs/cross/cpcca.py

@@ -982,8 +982,8 @@ def _compute_total_squared_covariance(self, C: DataArray) -> DataArray:
 
  Requires the unwhitened covariance matrix which we can obtain by multiplying the whitened covariance matrix with the inverse of the whitening transformation matrix.
  """
- C = self.whitener2.inverse_transform_data(C)
- C = self.whitener1.inverse_transform_data(C.conj().T)
+ C = self.whitener2.inverse_transform_data(C, unwhiten_only=True)
+ C = self.whitener1.inverse_transform_data(C.conj().T, unwhiten_only=True)
  # Not necessary to conjugate transpose for total squared covariance
  # C = C.conj().T
  return (abs(C) ** 2).sum()