Mathematica

numerical integration
hi, i have a pretty nasty double integral which i need to solve numerically but mathematica gives me error messages when i try to solve it straightforward using NIntegrate the integrand is: Exp[-I*\[Lambda]*(x+y)]*(x-y)*((Sinh[Pi*(x+I*\[Epsilon])]*Sinh[Pi*(y-I*\[Epsilon])])^-2 -(Sinh[Pi*(x-I*\[Epsilon])]*Sinh[... 1 Jul 2010 08:50

Export[] hi-res JPEG not affecting Axes|Plot Label->
Hello MathGroup: I am making some plots and exporting high-resolution JPEGs from them. But the AxesLabel and PlotLabels are not "scaled"ed with the desired resolution. As a result, although the graphic is "large", the user must scroll in to read the labels. Has anyone had this problem and/or found a workaround... 30 Jun 2010 02:10

Absolute value
I would like to calculate the absolute value of complex quantities. For example Abs[Exp[I phi1]+Exp[I*phi2]], which sould give 2 (1+cos(phi1-phi2)). However it does not work. I tried to use real numbers as assumtion, but it always answers "Abs[Exp[I phi1]+Exp[I*phi2]]". What am I doing wrong? Regards, Mark. ... 2 Jul 2010 07:59

Automatic Differentiation of mathematica code
Dear Experts, Is there any implementation of automatic differentiation in Mathematica? If I have a function that is completely numerical then I can use the ND function but that gives a finite difference derivative. Also for a function that is quite expensive to evaluate ND takes huge time to find the derivative.... 27 Jun 2010 05:15

function local/private to another function?
Hello; What is the best way to have a function which can only be "seen" and called by only the enclosing parent function? And not be in the global space (without using a package?). Is it something like: f1[x_]:=Module[{b,f2}, .... f2[y_]:=Module[{c},...c=y^2...Return[x]]; b=f2[x] ..... 27 Jun 2010 05:15

Circuit gains
Hello all, I am working on expressing the outcome of a characteristic polynomial in circuit gains. The gains are independent, however certain "entities" are common. This is expected and should result into more simple functions for the gains, however I cannot seem to achieve a "simple" substitution rule w... 26 Jun 2010 09:43

Particle Filters
Hi All, Does anyone have any guidance or examples on Mathematica's suitabililty around linearization of systems of nonlinear differential equations using particle filters? Thanks, Sander ... 26 Jun 2010 09:43

Orthogonalize in a discrete setting
I am trying to implement Orthogonalize in a particular scenario. First, I have L=3; pts=Table[n,{n,1,L}]; f[z_,n_]:=Product[1+z Part[pts,m],{m,1,n-1}] The z argument above will be taken from a list of complex numbers which I named zees (which also has length L), so z[i_]:=Part[zees,i] I want to orthog... 26 Jun 2010 03:18

how to automatically include own package into different demonstration
Hello; The problem: currently when I write a demo, I put all the code into one large Manipulate. When I write another demo, sometimes I'd like to use some of the functions I wrote earlier. What I do Now is simply open the old notebook, and with the mouse copy/paste the function code from the older demo note... 26 Jun 2010 03:18

coordinates on a single line of output corresponding
data = Flatten[ Table[{u, v, u + v, u - v, u*v/10}, {u, 0, 4.5, .5}, {v, 0, 3.5, .5}], 1]; Length[data] 80 data // Grid Bob Hanlon ---- Narasimham <mathma18(a)hotmail.com> wrote: ============= How to obtain data= Table[{u,v,u+v, u-v, u*v/10 },{u,0,4.5,.5}, {v,0,3.5,.5}] for 80 points ... 26 Jun 2010 03:18