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Jun
14
awarded  Civic Duty
Jun
13
comment Interprocedural optimization
It is possible to compute PrimePi[n] without enumerating all prime numbers less than $n$. See for example Lehmer's recursive formula.
Jun
13
revised How do you check if there are any equal arguments(even sublist) in a list?
Changed the name of the second function since it is no longer a Boolean function.
Jun
13
revised How do you check if there are any equal arguments(even sublist) in a list?
Include modifiication to keep track of repeated elements as per OP's request
Jun
13
answered How do you check if there are any equal arguments(even sublist) in a list?
Jun
13
comment Checking if the roots of a function are real
You can try checking that the imaginary part is zero. We can get the list of roots using x /. {ToRules[Reduce[LegendreP[6, x] == 0, x]]}. Then we map Im to each root using Map[Im,%], which gives {0,0,0,0,0,0}. This seems to suggest that the roots are real, but I am not 100% sure.
Jun
13
comment Splitting a list
@BrettChampion At one point I made a list of things I liked about Mathematica, and it included the fact that everything is an expression. Lisp popped up when I researched the roots of this feature. On a related note, that book really did teach me to write recursions! (Always ask null?, etc.)
Jun
13
answered Splitting a list
Jun
12
awarded  Nice Question
Jun
10
revised Implementing Central Symmetry
Chose a better reference, more accurate definition of orthogonal group
Jun
10
comment Wagner's trick to monitor FindRoot no longer works in Mathematica version 8
@AlexeyPopkov Thanks! Could you also include a link to the documentation where that "standard" trick is explained? I apologize for making so many requests of you.
Jun
9
comment How to Clear a symbol with subscript in Mathematica?
By the way, there is still one typo in your reply. You wrote Unset[Subscript[[Lambda], 0]], which is missing a backslash.
Jun
9
comment How to Clear a symbol with subscript in Mathematica?
I started with a fresh Mathematica session. In that case, Subscript[\[Lambda], 0] = 1 followed by Unset[Subscript[\[Lambda], 0]] does not generate any warning message. I can even do the assignment Subscript[\[Lambda], 0] = 2 after that. If you just want to clear $\lambda_{0}$, you probably do not need to use the Notation package. Maybe you made the problem worse by calling functions from that package?
Jun
9
comment How to Clear a symbol with subscript in Mathematica?
Have you tried Unset[Subscript[\[Lambda], 0]] instead of Unset[Subscript[Lambda, 0]]?
Jun
9
accepted Wagner's trick to monitor FindRoot no longer works in Mathematica version 8
Jun
9
comment Implementing Central Symmetry
Szabolcs' image uploader came in handy.
Jun
9
answered Implementing Central Symmetry
Jun
9
comment Wagner's trick to monitor FindRoot no longer works in Mathematica version 8
@AlbertRetey I am not sure I understand how that trick works in this context. Could you post an answer based on that?
Jun
9
comment Can a function be made to accept a variable amount of inputs?
+1 Your method is much cleaner than mine. It is good to know about Check too.
Jun
9
comment Wagner's trick to monitor FindRoot no longer works in Mathematica version 8
Evaluated is not listed as one of the options for FindRoot in the documentation. What does it do?