grtensor and maple 11

Pacopag

Hello everyone;
This is my first time in the physics forums, or any forum for that matter, so please accept my apologies if I am posting this in the wrong place.

I have just installed grtensorII into Maple 11. I am running it on Fedora 7. The install seems to have worked, although I did have to tweak some of the commands (compared to those in the install guide, which I guess was written for windows users) in order to get it to work. I can load the libraries, and I can load most of the pre-defined objects (e.g. Schwarzchild geometry, Ricci tensor, Christoffel, etc). My problem arises when I try to define new tensors. Even if I enter examples straight from the manual exactly as they are written, it spits out errors at me. Here's an example:
grdef ( 'u{a} := [0,f(r),0,g(r)]' ):
Here I am just trying to define a covariant vector, where the functions f(r) and g(r) are specified, but this just doesn't work. I am getting the syntax from Document D: Defining new Tensors, Section 5, Number 9, from the documentation that comes with GRtensor II.
There also seems to be a problem when I try to define a tensor with contravariant indices because the 'carat' character causes maple to think that I want to enter an exponent. If I override this with \^, it gives me an "invalid power" error.

Any help?

Pacopag

after hours of banging my head, I got it working. I was using forward quotes instead of back quotes around the assignment statement. Silly.

Cheers.

smirshekari

May I ask how did you teach Maple loading your metrics? I had a hard time to do that in OS X and still can't get any output from qload(mink) for instance.

implicitnone

@smirshekari: Is your GrTensorII installed correctly? If so, it should see the metric directory by itself. And of course, before

qload(mink)

do you call grtensorii by

grtw()

and while installing grtensorii, have you copied maple.ini to the maple directory?

smirshekari

Thank you. It is woking now, but I don't know how where are my metrics? :( Any preferred address to look up in?

ashmita

hello,
i am ashmita. i am using as operating system ubuntu11.10
and i have installed mathematica version 8.0. i am trying to add grtensor
package to mathematica. as per the instruction i have moved the
grii/directory to packages directory of mathematica then i have written
the command <<grii/grt.m to the mathematica notebook page and it is
displaying:

GRTensorM Version 1.2 for Mathematica 3.x
July 20, 1998
Copyright 1996-98 by P. Musgrave, D. Pollney and K. Lake
Update by Mustapha Ishak B.
Use qload[] or grload[] to load a metric.
?grtensor for help.
Metric directory = "/group/local/math/Packages/grii/metrics/"

.but then whenever i am writing suppose qload[schw] it is displaying:

Failed to read /group/local/math/Packages/grii/metrics/schw.g
$Aborted

I dont understand why this problem is occuring. I will be highly obliged
if you can give me any advise to resolve this issue completely.