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A PhD student in theoretical physics with a keen interest in numerical general relativity, high-performance computing, and C++.


Feb
14
revised Can I tell Simplify to prefer nested polynomials?
deleted 195 characters in body; added 3 characters in body
Feb
14
answered Can I tell Simplify to prefer nested polynomials?
Feb
14
comment Can I tell Simplify to prefer nested polynomials?
Thanks for this, it does seem to be an interesting idea. I should note, however, that my real concern here is not so much performance as floating point precision. If r is orders of magnitude away from 1 then 8 + 13 r^2 + 11 r^4 + 5 r^6 + r^8 is obviously a rather bad thing to be doing.
Feb
14
revised Can I tell Simplify to prefer nested polynomials?
edited body
Feb
14
revised Can I tell Simplify to prefer nested polynomials?
Clarified the point of the query
Feb
14
asked Can I tell Simplify to prefer nested polynomials?
Dec
6
awarded  Popular Question
Feb
12
comment Series command no longer expands arbitrary functions after aborting previous evaluation
Thanks, but I highly doubt it's related to that. I'm not trying to expand array of expressions, plus, both Series and SeriesCoefficient worked fine until now. (And they still do if I start fresh kernels). I guess there's not much I can do at this point other than restart and hope it doesn't occur again.
Feb
12
comment Series command no longer expands arbitrary functions after aborting previous evaluation
I've underestimated my expression. The culprit seems to be over 20000 lines long and I couldn't find a pastebin that wouldn't choke on it. If anyone's interested I've uploaded it in the form which can be quickly imported using MetricFG13=(<<"MetricFG13");. The command which caused the problem was SeriesCoefficient[MetricFG13,{\[Xi],0,4}]. (I think I let it run for something like 20 minutes before aborting.)
Feb
11
comment Series command no longer expands arbitrary functions after aborting previous evaluation
MathKernel is using just over 580MB. My system still has just under 4GB available though.
Feb
11
comment Series command no longer expands arbitrary functions after aborting previous evaluation
@rcollyer These are terms in asymptotic expansions of a curvature tensor in high dimensions, some of them are many hundreds of lines long and take hours to extract. Unfortunately I don't think I can reasonably paste the code which will duplicate my expressions in this space. I understand that I'm not making it easy for people to reproduce this condition, but I thought there might be some attribute which causes Series to avoid processing arbitrary functions.
Feb
11
awarded  Editor
Feb
11
revised Series command no longer expands arbitrary functions after aborting previous evaluation
deleted 8 characters in body; deleted 2 characters in body; added 1 characters in body; deleted 1 characters in body
Feb
11
asked Series command no longer expands arbitrary functions after aborting previous evaluation
Apr
9
awarded  Nice Question
Apr
8
comment Unsaved notebook is crashing: is there any way I can save the state of the MathKernel before I kill it?
I have coredumped the MathKernel and Mathematica processes in question and duly forced the crashing instances to close. I've re-done all my work, but if anyone knows an easy way to extract inputs from the dump (which is around 1.6GB of binary content) that'd be a great prevention against future crashes :)
Apr
8
comment Unsaved notebook is crashing: is there any way I can save the state of the MathKernel before I kill it?
Unfortunately, the notebook wasn't responding to my scrolling (or any other action for that matter) and the important bits of code were off-screen...
Apr
8
awarded  Student
Apr
8
asked Unsaved notebook is crashing: is there any way I can save the state of the MathKernel before I kill it?