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Nov
17
answered How do I determine the maximum value for a polynomial, given a range of x values?
Nov
17
comment How to draw a spring?
I was surprised that there is no Spring[] build in function in Mathematica Graphics actually. There should be form 3D and 2D. For dynamics and mechanical demos, it will be useful to have one with many options to use.
Nov
17
revised Passing lists to functions in a manner that works like pass-by-reference in other languages?
added 1085 characters in body
Nov
17
reviewed Approve suggested edit on Covariance of a P x M x N matrix
Nov
17
comment Seek a quick way to bring standard order back to original after Complement
@PinguinDirk, great, now you are telling us, after all this hard work :)
Nov
17
comment Seek a quick way to bring standard order back to original after Complement
@Kuba, it is a list (for ordered, not series). This is actually an important topic, since some CAS systems support both a set and a list as basic data types. Here is Maple page on this for example: maplesoft.com/support/help/MapleSim/view.aspx?path=set , so this sort of thing can be important in some applications...I remember this was talked about before at mathgroup.
Nov
17
comment Seek a quick way to bring standard order back to original after Complement
@Kuba, but you need to use the correct comparing operator then for comparing sets :) You are using an operator = whose semantics are not defined for use with true Mathematical sets. That is why I said "like" a mathematical set. But for this for another place to discuss I suppose.
Nov
17
revised Seek a quick way to bring standard order back to original after Complement
added 6 characters in body
Nov
17
reviewed Approve suggested edit on Limit of a complex function
Nov
17
answered Seek a quick way to bring standard order back to original after Complement
Nov
17
reviewed Approve suggested edit on Impact Crater Simulation
Nov
17
answered Limit of a complex function
Nov
17
answered Why the result by hand is different from the command “DSolve”?
Nov
17
comment Why the result by hand is different from the command “DSolve”?
If you simplify M answer, then it becomes: Simplify[%]; y[x] -> 1/50 E^-x (50 C[2] Cos[2 x] + E^x (-1 + 5 x) Sin[x] +Cos[x] (E^x (-7 + 10 x) + 100 C[1] Sin[x]))
Nov
17
comment Long run time for older code that ran fast in older versions
@cormullion I have all Trott books. I do not actually run any code, I just use them to read the code from the pages and try to figure what it does, but it is too advanced for me. 90% of the time I can't understand the code, but I like to look at it still because it looks amazing.
Nov
17
comment Why is `NMinimize` trying to evaluate my function analytically instead of numerically?
Just a wild guess, try adding ?_NumericQ to the argument of the function called. see support.wolfram.com/kb/3820
Nov
16
comment Passing lists to functions in a manner that works like pass-by-reference in other languages?
I just saw your edit. I do not know if this was after I answered or before. But I assume now it is all clear? Or is there still a problem?
Nov
16
revised Passing lists to functions in a manner that works like pass-by-reference in other languages?
added 322 characters in body
Nov
16
answered Passing lists to functions in a manner that works like pass-by-reference in other languages?
Nov
16
comment Passing lists to functions in a manner that works like pass-by-reference in other languages?
Mathematica passes things by value, not by reference, like in say Fortran. Yes, you can force by reference in M, but this requires extra setting. I'll post an answer if that what you want, but it is best to assign the result to s