221 reputation
19
bio website
location Cambridge, England
age 25
visits member for 2 years, 8 months
seen Dec 4 at 22:38

PhD student in numerical general relativity with a keen interest in high-performance computing, C++, and anything to do with programming.


Nov
20
comment How to exclude a region from ParametricPlot
Perfect! Thanks and apologies for my oversight in looking through the docs.
Nov
19
comment Non-separable partial differential equation in polar coordinates
It seems that NDSolve is sometimes a bit picky when it comes to elliptic equations. Just a quick query: are you sure there is actually a bound state solution for these parameters? I've run Eigensystem on the discretised Schrödinger operator and can't seem to find any sensible solution.
Nov
17
comment Symbol definition in parallel kernels
Also, Association is clearly an appropriate solution here which I will indeed use. However, the question still holds: is there a way to define to a symbol in the way described above from parallel kernels?
Nov
17
comment Symbol definition in parallel kernels
This was exactly what I was looking for before going with the "attching to data" route. Honestly, in my years of using mma I've somehow never come across this rather fundamental built-in. I did try searching for "HashMap in Mathematica" or some such earlier but somehow that yielded nothing useful. Thanks a lot!
Apr
28
comment Simplifying expression on power
I will add to the above that RuleDelayed can be invoked by replacing -> with :>.
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
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.
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...