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Aug
30
comment Simple exercise using the function Cases
Addendum: for a sufficiently long list, exploiting the short-circuit property of Or[] can be helpful: test for divisibility by $3$ first, since it's the easier test, and invoke the primality test only if that fails. So, x_ /; Divisible[x, 3] || PrimeQ[x]
Aug
30
comment How to delete subsets quickly?
I see. @yohbs, what if you use Union[] with an appropriate SameTest setting?
Aug
30
comment Combination of interpolations doesn't work?
Good warning. In short: if your data is sufficiently contaminated with errors, direct application of finite differences will likely yield crap. You could try smoothing, but that is now a different kettle of fish…
Aug
30
comment Simple exercise using the function Cases
I had Select[list, Divisible[#, 3] || PrimeQ[#] &] in mind, tho.
Aug
30
revised How to delete subsets quickly?
edited tags
Aug
30
comment How to delete subsets quickly?
Without sorting, how long does it take?
Aug
30
comment Simple exercise using the function Cases
Select[] might be more straightforward for you.
Aug
30
comment Undocumented function SumOfSquaresReps
"number of arguments etc." - as you can surmise from kglr's answer, it takes two arguments: Reduce`SumOfSquaresReps[k, n] returns all possible lists of k positive integers whose squares sum to n.
Aug
30
comment Visualising a 1-(50,15,15) design
@Shutao, it's block design notation.
Aug
30
reviewed Leave Open Remove color artifacts in overlay of several Graphics objects?
Aug
30
comment Calculating expected value from paired values and weights
Equivalent: Dot @@ MapAt[Normalize[#, Total]&, Transpose[m], 2]
Aug
30
revised Calculating expected value from paired values and weights
user's additional comments
Aug
30
reviewed Leave Open Removing an ordered pair from a list of ordered pairs according to a certain criterion
Aug
30
reviewed Leave Open How to assert that a list of variables is real in a nice and clean way
Aug
30
comment Decouple 3 simultaneous 2nd order ODEs (of 3 dependent variables)
Why impose initial values for the second derivatives if your ODE is second-order?
Aug
30
comment Calculating expected value from paired values and weights
Times @@@ list?
Aug
30
comment How to create pairwise difference matrix entry?
Did you do what I said and look at the docs?
Aug
30
comment How to create pairwise difference matrix entry?
Look up Outer[].
Aug
30
awarded  Notable Question
Aug
30
revised Visualising a 1-(50,15,15) design
edited tags