Demonstration 2 (rnds1): Automatic generation of an NPtetrad and calculation of the Petrov type, and Ricci scalars.
> restart:
> grtw();
> qload(rnds);
![`x `^a = vector([r, theta, phi, t])](images/rnds111.gif){kind=small}
> nptetrad([r,t]);
The metric signature of the rnds spacetime is +2.
In order to create an NP-tetrad, the signature of g(dn,dn) will be changed to -2.
Continue? (1=yes [default], other=no) :
nptetrad> 1;
> grcalc(Petrov);
`Basis/tetrad related object definitions`
`Last modified 23 January 2001`
Created a definition for e(bdn,dn,pdn)
> grdisplay(_);
> PetrovReport();
> grcalc(RicciSc);
> grdisplay(_);
>