Mathematica

Trouble with coupled quadratic equations where the
Robert Hoy wrote: Hello - sorry for the extremely belated reply. Daniel, your method worked, of course - thanks. What I ended up going with was a numerical solver that makes initial guesses (with some randomnness) as to the values of the {x, y, z}, and then uses Newton iterations to try and solve... 12 Mar 2010 07:12

Havriliak-Negami fit in Mathematica?
Hi, I have frequency,epsilon(real),epsilon(imaginary) data in three columns. I need to fit with Havriliak-Negami relaxation function in Mathematica. I do need help from you. Please help me. ... 11 Mar 2010 07:48

Struggling with FindFit for a model which takes results from
Hi Steven, Your main problem seems to be the numerous syntax and logic errors in your code: 1. p is undefined 2. you use numbers such as 1*^15 where you mean 1*10^15 (*missing 10 *) 3. missing bracket in insolutemolefxlist[t_] := {XinSalt[t],XinCPA1[t] 4. variables A and NinWater0 run together to form the ne... 12 Mar 2010 08:18

elementary questio about packages
Dear List: I made a package with a function that has a minimization. The minimization returns, as should be, the value of the optimization, and then the values of the variables, in the form {z1->10,z2->20,z3->50}. In the notebook, this works perfectly well. In the package, however, the function throws back the... 13 Mar 2010 08:37

bad Mathieu functions
I am no expert in Mathieu functions, but I don't think this gives the right result: ce1[r_, q_, z_] := MathieuCPrime[MathieuCharacteristicA[r, q], q, z] Plot[I ce1[3, q, I], {q, 0, 1000}] In another system you get a smooth graph, making very small oscillations about zer o as q increases. I've read that Mathi... 14 Mar 2010 06:31

ParametricPlot3D with three parameters
Clear[t,ph]; R=1; ph = Pi/8 ; line=R{Cos[ph]Cos[t], Cos[ph]Sin[t] ,Sin[ph]}; Lati=ParametricPlot3D[line,{t,0,Pi}] surf=Table[R{Cos[ph]Cos[t], Cos[ph]Sin[t] ,Sin[ph]}, {ph,0,1.3,.12},{t, 0,Pi,Pi/16.}]; Needs["Graphics`Graphics3D`"]; sph=ListSurfacePlot3D[surf] Show[{Lati,sph},PlotRange->All] hypsurf=Table[R{ Co... 12 Mar 2010 08:18

Setting default zoom factor in notebooks
Hi, I've this problem, I often work with zoom factor 125% in my notebooks and i would like to make it default zoom. How can I do it ? I'm using Mathematica 7.0.1.0 in OSX 10.6.2 . Thank you in advance ! Nicola ... 12 Mar 2010 08:18

gaps in plot of piecewise function
Hi, I want to plot a piecewise function, but I don't want any gaps to appear at the junctures. An easy example is: s[x_] := Piecewise[{{-Sqrt[2]/2*Sqrt[-x + 0.5] + 2, x < 0.5}, {2, x >= 0.5}}]; Plot[s[x], {x, 0, 1}] It should be clear, that the piecewise function defined above is continuous, even at x=0.5... 13 Mar 2010 08:37

ZTransform for a non-causal unstable signal. How to make Mathematica
Hi Nasser, Mathematica calculates the unilateral Z transfrom. This is clearly zero in your case. But in your case you may get the bilateral by setting n -> -n in f: f = (-(1/2)^(-n))*UnitStep[n - 1]; ZTransform[f, n, z] Daniel On 10.03.2010 07:45, Nasser M. Abbasi wrote: Hello; I am trying to find... 11 Mar 2010 07:48

Import data as vector (not two dimensional Table)
Try ReadList["sample.dat"] Adriano Pascoletti 2010/3/10 Artur <grafix(a)csl.pl> Dear Mathematica Gurus, Who know how import data from file "sample.dat" when file is of the form 2 3 5 7 directly as vector {2,3,5,7} Because after procedure Import["sample.dat",'Table"] we hav... 10 Mar 2010 07:28