Unanswered Questions
582 questions with no upvoted or accepted answers
49
votes
0
answers
3k
views
Fast Spherical Harmonics radiative transfer
This is a rather specific question and I apologize for spamming you with some lengthy code. But it could be interesting for some reader and maybe you can help out, so please bear with me.
I am using ...
- 141
43
votes
0
answers
1k
views
Performance problems in new Sequence functions
The new-in-10.1 Sequence* family of functions should provide newly optimized methods for handling sequence problems. Happily in some cases they do! For example ...
CommunityBot
- 1
21
votes
0
answers
459
views
Internal`Bag memory usage
1. How does Internal`Bag handle memory inside a compiled function? (examples below)
2. Is there a way to explicitly free up memory used by ...
- 275k
15
votes
1
answer
438
views
DateInterval Min/Max performance issue
Bug introduced in 12.1 and persisting through 14.0.0
Update
WRI has confirmed that this is a bug. CASE:4521676
The performance of Min and ...
CommunityBot
- 1
14
votes
0
answers
487
views
Why is MemoryInUse[] Very Different from the Actual Amount of Memory Being Used?
I call the MemoryInUse[] function, and it outputs about 256 Megabytes.
MemoryInUse[]
(*255979528*)
However, my activity ...
- 1,637
13
votes
0
answers
342
views
Linear programming with lazy constraints
Does Mathematica offer any means for solving linear programming problems with "lazy constraints", as described e.g. here?
While I am not very familiar with linear programming, my understanding of the ...
- 62.5k
13
votes
0
answers
176
views
What changed in String handling between 11.0 and 11.3?
I was trying to optimize some String-handling code here using my standard trick of converting it to a list of bytes first and using basic list operations instead of ...
- 48k
13
votes
0
answers
246
views
Why does GreaterEqual take a long time to evaluate with arrays?
Take the following example:
big = RandomReal[1, 10000000];
Head[big >= 0.66] // AbsoluteTiming
(* {0.53489, GreaterEqual} *)
Why does this take a long time ...
- 239k
13
votes
0
answers
333
views
Slow JoinAcross performance
Bug introduced in 10.3
I am using JoinAcross to combine two datasets, where the key is an Integer.
...
- 239k
12
votes
0
answers
232
views
Mathematica is getting slow when repeatedly calling an external program
I found a strange phenomenon that Mathematica is getting slow when I repeatedly called an external program by using ReadList. For example, the following code will display a significant increase of CPU ...
- 25.6k
11
votes
0
answers
330
views
What is the best and most efficient way to curry?
Suppose I have a function with a signature like g[expr, _?(f), {1}, Heads -> False] and I want to access it as an operator by giving the first argument last. I ...
- 10.4k
11
votes
0
answers
180
views
Performance warning using TakeList and All on big lists
According to Mathematica's own documentation, TakeList can operate with lists containing All. For example:
...
- 37.7k
11
votes
0
answers
856
views
How to speed up calculations on big symbolic matrices?
this is my first time posting something on a community of the StackExchange platform, so please feel free to correct me if I'm doing something wrong. :) Additionally you should probably know that I'm ...
- 275k
11
votes
0
answers
412
views
Call Magma in Mathematica
I've written some code in Mathematica, related to some group theory questions I have. Subsequently, I found that part of the code could be significantly sped up if I could just call a routine in ...
- 459
11
votes
0
answers
408
views
Efficient image stacking
I have a list of lists of images that I would like to stack and create mean images for each list of images.
Images are .jpg files 2592x1944 pixels large. Each list ...
CommunityBot
- 1