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03:37
@MichaelE2 on a little InterpolatingFunction bender tonight?
03:59
@ChrisK Yep. Every now and then I look up the unanswered questions on some tag. Earlier today I clicked the interpolation tag. Often I find unanswerable questions, tbh, so it's not really a great way to spend time. Different today though.
Fouled some off into the Review queue, too. (If you get baseball metaphors. :)
@ThunderBiggi I missed this question earlier. If you mean the ComplexityFunction, it penalizes expressions that contain Sin[] or Cos[] and encourages Simplify to choose expressions that don't contain them.
 
3 hours later…
07:06
@MichaelE2 that is something useful I learnt!
Any ideas how to test whether the simplify thing is a bug?
 
3 hours later…
09:50
Unsure if I'm not smart enough for this question or if it's an April fool's joke :) mathematica.stackexchange.com/questions/266006/…
 
5 hours later…
14:32
@ThunderBiggi The simplest would be to report it to WRI. As a user, it's dissatisfying, no? So whether it's technically a bug or not, I can't imagine anyone not preferring the Sin & Cos to simplify to 1. It turns out ComplexityFunction -> LeafCount solves the problem, too. The problem is with Simplify`SimplifyCount and...
-(1/4) (-4 + x1^2 + x2^2 + x3^2 + x4^2) automatically becoming 1/4 (4 - x1^2 - x2^2 - x3^2 - x4^2), which is 6 leaves more complex. This distribution of the sign does not happen when the Sin/Cos factor is present. SimplifyCount adds a penalty beyond the leaf count to it so that the Sin/Cos factor is not eliminated. Strange edge-case.
-(1/4) (-4 + x1^2 + x2^2 + x3^2 + x4^2) // Hold // LeafCount  (* compare Simplify`SimplifyCount *)
1/4 (4 - x1^2 - x2^2 - x3^2 - x4^2) // Hold // LeafCount

-(1/4) (-4 + x1^2 + x2^2 + x3^2 + x4^2) // Hold // ExpressionTree
1/4 (4 - x1^2 - x2^2 - x3^2 - x4^2) // Hold // ExpressionTree
14:50
@CarlLange definitely a joke. I had to resist my inner urge to downvote it as nonsense.
at least this stack exchange site isn't changing the theme like stack overflow
 
2 hours later…
16:26
posted on April 01, 2022 by Matthew Sottile

Each issue of the Mathematical Association of America’s Math Horizons presents readers with puzzles to solve, and the April 2021 issue included the “Knightdoku” challenge created by David Nacin, a math professor at William Paterson University in Wayne, New Jersey. In this puzzle, a simple Sudoku-like problem is described based on chess knights. Each cell […]


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