I am using GRQUICK package for calculation of Ricci tensors. I am using a non diagonal metric with coefficients being functions of two co-ordinates. I want to know if the highlighted expression denotes partial derivates or something entirely different.
1 Answer
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Well, you need to see help on D
.
D[v[r, t], t] (*it gives partial derivative of v w.r.t t once*)
Here the superscript (0,1)
means that v[r,t]
is partially differentiated once w.r.t t
thats why you have 1 on right side because in the argument [r, t]
, t
is on the right side.
Now, if you want to differentiate v
w.r.t r
, then
D[v[r, t], r] (*it gives partial derivative of v w.r.t r once*)
D[D[v[r, t], r], r] (*it gives partial derivative of v w.r.t r twice*)
Does this make any sense?
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$\begingroup$ Yes ! Many thanks. Now its crystal clear :-) $\endgroup$ Feb 22, 2017 at 7:34
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v[r,theta]
w.r.ttheta
once. $\endgroup$FullForm
to check what is there. $\endgroup$