wolfram-mathematica

I am wondering how I can write a function to be used in the Apply function in Mathematica? For example, I want to trivially re-implement the Or function, I found the following Apply[(#1 || #2)&,{a,b,c}] is not okay since it only Or 'ed the first two elements in the list. Many thanks! This will work, no matter how many vars, and is a general pattern: Or[##]&, for example In[5]:= Or[##] & @@ {a, b, c} Out[5]= a || b || c However, in the case of Or , this is not good enough, since Or is HoldAll and short-circuiting - that is, it stops upon first True statement, and keeps the rest unevaluated.

I have a linear recurrence problem where the next element relies on more than just the prior value, e.g. the Fibonacci sequence. One method calculating the n th element is to define it via a function call, e.g. Fibonacci[0] = 0; Fibonacci[1] = 1; Fibonacci[n_Integer?Positive] := Fibonacci[n] + Fibonacci[n - 1] and for the sequence I'm working with, that is exactly what I do. (The definition is inside of a Module so I don't pollute Global` .) However, I am going to be using this with 2 10 - 2 13 points, so I'm concerned about the extra overhead when I just need the last term and none of the

I have developed some code to generate random variates from the product of a LogNormalDistribution and a StableDistribution: LNStableRV[{\[Alpha]_, \[Beta]_, \[Gamma]_, \[Sigma]_, \[Delta]_}, n_] := Module[{LNRV, SDRV, LNSRV}, LNRV = RandomVariate[LogNormalDistribution[Log[\[Gamma]], \[Sigma]], n]; SDRV = RandomVariate[ StableDistribution[\[Alpha], \[Beta], \[Gamma], \[Sigma]], n]; LNRV * SDRV + \[Delta] ] (* Note the delta serves as a location parameter *) I think this works fine: LNStableRV[{1.5, 1, 1, 0.5, 1}, 50000]; Histogram[%, Automatic, "ProbabilityDensity", PlotRange -> {{-4, 6}, All}

I have a reference number of the following type DAA76647.1 which I want to convert unchanged to a string in Mathematica. That is myfn[DAA76647.1] gives as output "DAA76647.1" Is there an easy way to do this? (The input cannot be a string and, other than conversion to a string, I do not want to change the input in any other way). Update ToString /@ {A1234, 1234.1, A1234 .5} gives the following output (where I have simply entered everything from the keyboard) {"A1234", "1234.1", "0.5 A1234"} It appears that if what goes before the decimal point is alphanumeric, there is a problem. Possible

I've run into what seems like a bug in Mathematica 8. I can't find anything related to it online, but I admit I'm not exactly sure what to search for. If I run this statement: 0.05 + .10 /. {0.15 -> "pass"} 1.04 + .10 /. {1.14 -> "pass"} 1.05 + .10 /. {1.15 -> "pass"} 1.15 /. {1.15 -> "pass"} I get this output: pass pass 1.15 pass Am I just overlooking something? Edit: After reading the helpful discussion below, I changed my dispatch table to use a Which statement instead: f[x_] := Which[x == 1.05, -1.709847, x == 1.10, -1.373823, x == 1.15, -1.119214, x == 1.20, -0.9160143, x == 1.25, -0

I have a graph as a result of executing ListPlot[] function. I can manually edit this graph by moving points to a different location and also adding new points using the Drawing Tools . How do I get the coordinates of new and changed points from the edited graphics? This approach makes every data point a locator that can be moved. New locators can be added and old ones deleted as appropriate. The best fit and variance are updated after every change. Here's some data of some exponential growth with some errors and a data point missing data = Delete[Table[{t, (1 + RandomReal[{-.2, .2}])Exp[t]},