Mathematica Definition and 1000 Threads

Does anyone know how to express a given function as a sum in mathematica using sigma notation? For example, I know how to make ##e^x = 1 + x^2/2 + x^3/6 + x^4/24...## but how would I have mathematica write it as ##e^x = \Sigma_{n=0}^{\infty} x^n/n!##? Thanks a ton!

I am giving the following input to Ti-89 Titanium: limit(S((2 x cos(100 x Pi x t)+2 x sin(10 x Pi x t))2 ,t,-t1,t1)/(2 x t1),t1,inf) where S is the integral symbol, Pi is π = 3.14, x is the multiplication symbol and inf is the infinity symbol The TI-89 answer is undef If I do it by hand it...

Hi there I am trying to find bound state energies assuming infinite potential. I have been told it can be done by analytically solving Right Hand Side and Left Hand Side of an equation such as: E^1/2 tan(2ma^2E/4hbar)^1/2 = (V0-E)^1/2 If solved properly, it should give one curve (RHS), crossed...

I have equation of motion that our instructor wants to replace one or both of the masses with a negative mass in Mathematica. I tried m1=-m1, but I get an infinite recursion. What is the best way to do this? The equations of motion is a monster, so I don't really want to do this by hand...

Hey guys, This is my first post here, so I will apologize in advance in case I'm posting this in the wrong section. I wrote a very simple function to calculate spherical harmonics in matla, and I used this function during 3 years. Yesterday I found that the function was actually wrong, and...

Dear all, I have time-series data, from which I would like to compute the tricoherence. After some googling, it seems that I will have to write my own code. But before I begin, let me ask this. Do anyone here know of a code, library (fortran, c), module (python, matlab, IDL, mathematica)...

I am trying to integrate a very messy expression using Wolfram online integrator but I get the message: "You need to use Mathematica to evaluate this expression". The online integrator works only for relatively simple expressions. Unfortunately I do not have a license for Mathematica. Any...

Hi All: I am an electrical engineering undergrad. I would like to learn a math plotting software which would be helpful in visualizing topics in advanced calculus (my immediate need). It would also be helpful if the math plotting software was of some use in electrical engineering, but this is...

Dear All, I need to design a magnetized iron calorimeter detector (HEP ex). There will be current coils (in the vertical plane) that will generate x-y magnetic field within iron. Given the detector boundaries and exact locations of the coils (i.e. all the B.C.s), I need to obtain the...

Plotting results from "for" loop Hello, I have a problem which it seems I couldn't solve. I have "for" loop which gives results of some calculations as, say, vectors with two coordinates. What I want is to plot the result as a point in the xy plane. This loop goes on and on with the...

At this point, I have about $45 credit in my iTunes account from gift cards given to me for Christmas. I was wondering if there are any useful apps out there that I can get for physics? Whether they are good now for while I am in college, good for work in the field post-college, or both. For...

Hi, I can't quite figure out what I'm doing wrong here. I tried restarting mathematica as well which is what fixed my previous problem Clear[eqn, soln, u, x, y] eqn = D[u[x, y], {x, 2}] + D[u[x, y], {y, 2}] == 0; soln = NDSolve[{eqn, u[x, 0] == Sin[x], u[0, y] == 0, u[1, y] == 0}, u[x...

EDIT: I left out something of major importance, I want to maximize with respect to a! Good day, I've run into an issue in solving a certain problem with matlab, and I was hoping if anyone could help me out. I am relatively new to matlab, so I don't even know if this is possible, but I...

I have a function of two variables F[x_,y_] and I Would like to integrate over one variable only and get a function G[x] for example and work with it. I want something like: G[x_]:=NIntegrate[F[x,y],{y,0,\infty}] But it doesn't work.

I have a 3D Plot in Mathematica and I would like to get coordinates for points (all points) that were plotted.

Dear all, here is my animation of a simple plot: Animate[ ParametricPlot[ {Sin[tf], Cos[tf]}, {tf, 0, t}, PlotStyle -> {{Thickness[0.002], Red}, {Thickness[0.002], Blue}}, PlotRange -> {{-2, 2}, {-2, 2}, {-2, 2}}, AspectRatio -> Automatic], {t, 0.01, 100, 0.01}, AnimationRate -> 2...

Hi everyone: I would like to join all elements of on matrix into just one list: matrix = 1 2 3 4 5 6 7 8 9 into list = {1,2,3,4,5,6,7,8,9} Anyone has a solution for this? Thanks

Hello, I am a novice in Mathematica, but insisting to learn it. I would appreciate help in solving the following problem: (*a=1;Which[a==1,x,a==2,b]*) list := List[1611, 1612, 1613, 1614, 1615, 1616, 1617, 1618, 32, 10] For[i = 1, i < 4, i++, a = list[[i]]; Print[a]...

I'm trying to do a calculation which involves taking the derivative of a term that is millions of terms long. I'm using a supercomputer right now with Mathematica to do it but it's taking to long. Does Matlab have a faster algorithm for computing derivatives analytically?

Hi guys, I have a system of six equations and thirteen variables. I would like to reduce it to seven free parameters. I used Reduce to solve it but it is taking really long (one full day and no output yet) and I think there must be a better way. Here is my code Y = {{y1}, {y2}, {y3}} T =...

Hi, I am not really sure this is the right topic to post my question in, but it is homework so... To my data in txt file I fitted a function ##f(x)## where ##x\in [0,100]##. In the original file I had only 100 points, but now that I have a nice polynomial fit, I can get infinite number of...

If I have a function depends on for example 2 parameters f[a,b], and I know the value of this function should range between 300 < f < 400, how I know the possible ranges of the parameters in Mathematica. Bests, S.S.

I have an ODE ##e^{2x}H(Hv'(x) + H'v' + Hv'') + (k^2 - 2e^{2x}H^2(1 + \frac{H'}{2H}))v = 0## where ##H(x)## is a known function that Mathematica has stored as an interpolation from a previous ODE and ##v(x)## is the unknown function to be solved for. ##k## is the adjustable parameter. Using...

Integrate[f[qs] DiracDelta'[qs (1 - 1/x)], {qs, -\[Infinity], \[Infinity]}, Assumptions -> 0 < x < 1] Integrate[f[qs] DiracDelta'[qs - qs/x], {qs, -\[Infinity], \[Infinity]}, Assumptions -> 0 < x < 1] This is on Mathematica 8 for windows. The results differ by a sign. They are effective...

I said to Mathematica to plot a graph as this: Plot[Exp[-Sqrt[-x]] + Exp[Sqrt[-x]] - 2 == 0, {x, -10, 40}]. You can see that there is square root of -x, which should mean that the function is defined only for x<=0. But no, Mathematica would plot a curve also for positive values of x. How...

I have a function that is defined using a variety of things, some matrix algebra, some mathlink functions, etc. But they are all defined to evaluate when called with the parameters : chi2[mb, vmc, v1, v2, v3, v4, 0.1066, 0.219] gives me a number back. I can even do a table over some range...

Hello, I want to fit a two-parameter function to two points in this way: FindFit[{{0, 1}, {1, 0}}, D + C *Log[-1 + Sqrt[-C^2 + (-1 + x)^2] + x], {C, D}, x] But Mathematica won't give the values for parameters C and D. Instead it says: "FindFit::nrlnum: "The function value {0...

There is a vector ##v_i(t)## (i=1,2,3). How to define the three functions in Mathematica? What about ##t_{ij}(t,\vec{x})##? I am trying to solve my vector and tensor equtions with Mathematica. Analytical solution would be perfect but numerical solution would also be fine. Actually I am not...

Determine all three-digit number ,##N##, having the property that ##N## is divisible by 11, and ##\frac{N}{11}## is equal to the sum of the square of the digits of ##N##. This cannot be solved just by guessing. I think I should use mathematica for this,but, this sum of the digits is a scary...

So when i use the following command, I get the following error DSolve[y'[x] - y[x] == 3, y[x], x] DSolve::deqn: Equation or list of equations expected instead of False in the first argument False. >> But when i change the variable y[x] and y'[x] to s[x] and s'[x], It works why is this...

In Mathematica, I computed the integral ##\lim\limits_{n\to\infty} \frac{1}{n^2} \int\limits_{0}^{\frac{\pi}{2}} \frac{\sin((2n+1)x)}{\sinh(x)} \ dx## and it incorrectly output the answer ##-\frac{3\pi}{2}##. I wanted to try a different CAS software that might provide a different answer, but so...

Hello, I've been using mathematica the past few days and quite like it. I am trying to add some figures to my word document. Because of the size of the exported emf file from mathematica, I am unwilling to have a document that is 100MB in size. So I was searching for some ways to export...

I have an integrand with a handful of terms, and some of them have poles in the denominator of the form (x+c) (but not all). There are three poles in total, and I want to collect all the terms according to each pole individually (eg all the terms with (x-1) in the denominator, (x-5), etc.)...

If I define a function, such as f[x_, y_] := {-2 x + 2 x^2, -3 x + y + 3 x^2} I can compute the derivative with D[f[x, y], {{x, y}}] but what is the syntax for evaluating this derivative at a point?

Hello, I'm just testing out mathematica for the first time. I was hoping someone could help me make sense of this input (see attached screenshot). I'm sure I'll be running into more peculiarities as I get more comfortable with the software, Ill post them in this thread as the pop up. Help much...

Hello, I told Mathematica to do a few calculations as follows: a = 0; b = 1; n = 4; For[i = 0, i < n, i++, p = 2*x*b - 2*i*a; a = b; b = p] c = CoefficientList[p, x]; l = Length[c]; m = 0; For[i = 1, i < l + 1, i++, r = Abs[Part[c, i]]/Abs[Part[c, l]]...

Hello, I know that in Mathematica one can define a function as follows: f[x_]:=x^2. The problem is, I get a polynomial from a for loop as an expression p=a*x^n+b*x^(n-1)+... Now I want to evaluate the polynomial at a specific point. I tried to define a function from the polynomial as...

Dear every Mathematino-s in high energy physics I knew several workers in computer and mathematics, but few of them know wolfram mathematica software, so I think it is justified to let my question appear here. I use wolfram-mathematica to make 3D figures and want to use them...

Val[a_] := ToCharacterCode[ToString[a]][[1]]; GH[a].GH[b].GH[c].GH[d].GH[b] //. {GH[a_].GH[b_] :> If[Val[a] > Val[b], GH[b].GH[a], GH[a].GH[b]]} I have the noncommutative multiply of GH[a].GH[b].GH[c].GH[d].GH[b] My goal is to order these in increasing charcter value. (Val is the function...

Solve[x - 2 cos[x] == 0, {x}] this is my imput but i get an error. What is the command to solve trig functions in mathematica thanks. I searched online but no avail.

I'm trying to integrate the function Exp[-I*t*x - t^2/2] from -infinity to infinity using NIntegrate in Mathematica; the value that I get is accurate when x is small, but as x gets larger, the output from NIntegrate does not match the value I get when I use Integrate -- it gets less and less...

Hey, Say I have a function f[a,b,c] which depends on another function g[b,c] such that: f[a,b,c] = a*g[b,c] If I input, f[a,1,2], mathematica spits out a*g[1,2] rather then actually evaluating what g[1,2] is. Is there a way I can force mathematica to evaluate g[1,2] so instead, e/g if g...

Here is the code, I am using Mathematica 7 with no packages installed at the moment. $Assumptions = 0 < u <= 19/80 && I10 \[Element] Reals; FXN = Sqrt[(u - 15/16)^2 - 2/5 (u + 17/16) + 1/25] (I10 (u^2) - 1/u); PA = Integrate[FXN /. {I10 -> 1/2 Log[1/2]}, u]; PB = Integrate[FXN, u] /...

I have been using Maxima to help me review to go back to grad school for physics. I think I might be running to the limits of its functionality (or maybe I just don't know how to use it correctly). I used to have a lot of experience with Mathematica, but their license system has grown to be...

Hi, I note that in the 'more info' for NonlinearModelFit it says that it assumes the values are normally distributed around the mean response function y, which I understand is required if one wants to use maximum likelihood methods and construct confidence intervals etc. However, there appears...

I'm trying to solve this ODE R'(t)=\frac{-a}{R(t)^2} numerically in Mathematica (a, b are non-zero constants). Here's what I have: NDSolve[{R'[t]==-a/R[t]^2, R[0]==b, WhenEvent[R[t]==0, end=t; "StopIntegration"]}, R, {t,0,1}] It's returning with NDSolve:::ndnum : Encountered...

Hi guys, I'm currently working on a project related to Faraday instability, and I of course came across the dispersion relation for capillary-gravity waves, i.e. ω² = tanh(kh)(gk + σk³/ρ) . Now I would need to numerically solve this relation for the wavenumber k as a function of depth h...

Instead of giving the results of the calculation, Mathematica says: "Tag Times in 0 × 1.52098*10^11 is Protected." as in the attached file. Anyone has any idea how to get the results?

I have a statement that looks like : vD.vD.vD.vD Where vD is noncommutative (but that doesn't really matter) I want to replace it so that each vD becomes v[a].D[a] But I would like it so the "a" is not repeating. So I need somehow a function that each time it is run returns it with...

Hello,I need help in Mathematica,my problem is that I wrote the system of differential equations and I put a certain value of the variables and it is supposed that the value of the absolute of the determent would be zero but unfortunately I did not get zero , I got another answer when I put...