I have a quick question about the GW extraction using the WeylScal4 thorn in the Einstein Toolkit.

The thorn uses the description of http://journals.aps.org/prd/pdf/10.1103/PhysRevD.65.044001 to calculate the Weyl scalar, right? (which seems to be the same as described in the numerical relativity book by Baumgarte and Shapiro, if I am not mistaken)..

Is this way of calculating the Weyl scalar equivalent to the one that uses the electric and magnetic part of the Weyl tensor (like for instance in the Book by Alcubierre or in i.e. http://arxiv.org/pdf/0910.3803v1.pdf)?

It seems that the method implemented in the ET has extra factors of R_{ijkl} compared to the one using the electric and magnetic parts of the Weyl tensor.

thanks a lot, 

Vassili