Mathematica

integrate log*sinc
Hi All, For Integrate[Log[x] Sin[x]/x, {x, 0, \[Infinity]}] Mathematica returns -EulerGamma \[Pi]. How to proof this analytical? I've tried to use residue theory but it seems not suitable since integrand has pool of second order in zero (for Jordan lema should be first order only). Substitution x=Exp[y] retur... 20 Apr 2010 15:52

Laplace transform of periodic function
Is there some way to tell Mathematica that a function is periodic when using LaplaceTransform to calculate its transform? For example, if I define... f[t_ /; 0 <= t < 1] := t - UnitStep[t - 1/2] t + UnitStep[t - 1/2] (1 - t) f[t_] := f[t-1] .... and then try LaplaceTransform[f[t], t, s] ... 16 Apr 2010 06:09

Function making white spaces
Dear community, I know that Mathematica has a built-in function that places a defined number of white spaces and may be used with say, Print operator. I cannot however, recall its name, or find it in Help. Please give me a hint, what is it? Best, Alexei -- Alexei Boulbitch, Dr., habil. Senior Scientis... 16 Apr 2010 06:09

Directed Hamiltonian Cycles
I could be overlooking something, but there seems to be no mention in the documentation (Version 7.0) that HamiltonianCycle and HamiltonianQ do not work properly for directed graphs. Not only that, they fail in a misleading way, returning a result with no warning that it's probably bogus. This is noted in the Mat... 15 Apr 2010 00:28

make arrows same size in VectorPlot?
With the Mathematica 7 function VectorPlot, is there an option to make all the arrows have the same length (and same head size)? The option VectorScale does not seem to allow that. Obviously the effect of such an option could be achieved by explicitly normalizing the vector field being plotted, but that takes... 17 Apr 2010 06:24

Through[(a+b+b)[x]]
Through[(a+b)[x]] yields a[x]+b[x] as expected, but Through[(a+b+b) [x]] yields a[x]+(2b)[x]. Through[(2b)[x]] yields 2[x]b[x]. Now, I can obviously get around this in this specific case, but generically is there a way to solve this so that Through[(a+b+b)[x]] yields a[x] +2b[x]? The case where I envisage this happ... 16 Apr 2010 06:09

BIOKMOD 5.0, a Mathematica tool for biokinetic modeling, fitting and
New version 5.0 of BIOKMOD is available at http://web.usal.es/guillermo/biokmod.htm This version expanded considerably version 4, including practically all ICRP current isotopes. Mathematica 7 is required. The program help has been enhanced. It is included some notebooks where they are described details (computati... 15 Apr 2010 00:28

Locator appearance
Dear community, I use Locator to pick up some points of the graph originated form experiment. In this case I would like to slightly modify the Locator appearance, since the gray ring on its background sometimes prevents me from seeing the point I want to pick up. I would like to leave its cross structure as ... 16 Apr 2010 06:09

Pade Approximation (further generalizations?---feature request)
I've been playing around with PadeApproximant[] in Mathematica and have been really impressed at the accuracy of the approach. According to Wikipedia: A Pad=E9 approximant approximates a function in one variable. An approximant in two variables is called a Chisholm approximant, in multiple variables a Canterbu... 28 Apr 2010 07:13

NIntegrate Confusion
Hi everybody, I'm using Mathematica 7.0 , i would like integrate numerically something like Fourier coefficients, my programe code contains: M = 50; f[t_] = 100 Sin[5 t]; basis = Table[Sin[n t], {n, 1, M}]; coef = 2/Pi*Table[NIntegrate[f[t] Sin[n t], {t, 0, Pi}], {n, 1, M}] in result it gives : NInte... 14 May 2010 09:29