Mathematica Definition and 1000 Threads

Hi I am trying to do some problem from the book "Student's Introduction to Mathematica" 2ed. I have shown the snapshot of the problem in 1.png. My attempt is a snapshot in 2.png. Please suggest some ways to do this correctly. thanks

Hi guys, I seem to still be having problems formatting polynomials in a standard way in Mathematica. I generate them randomly and would like them output using Print in a particular format. Say I have: theFunction=-2 + w^3 (-9 - 3 z) - 7 z + w^2 (4 + 5 z) + w (8 - 2 z^2) + w^4 (-5 z^2...

Hello everybody! I'm a new member and I don't know if it is the right section, but I have some problem with the software mathematica so I'm here hoping that someone can help me.. I have a csv file and I have to plot it, but I don't know which function I have to use. The csv file contains 3...

I just got mathematica and I wanted to use it to simplify 4 vector/ Lorentz transformations by using matrices etc. I was wondering how I would go about doing this. I just started special relativity in my first semester Quantum Mechanics/S.R. class for reference.

How can I get Mathematica to construct a cobb webb for $$ N_{t+1} = \frac{(1+r)N_t}{1+rN_t} $$

Hi Say I have a data set (x_i, y_i) such as of the form { {4.4077, 8.41282*10^-7}, {9.39964, 3.3636*10^-6}, {14.3781, 7.56237*10^-6}, {19.3462, 0.00001343}, {24.3073, 0.0000209557}, } The first coordinate is time, the second a weight. The sum of the weights equal 1, so I am...

I'm trying to analyze a fairly large (order 10^3) collection of PDB files to look for cation-pi interactions for a class. This requires me to parse each PDB file into a table which gives the position of each atom in the file. To do this, I've written the following code...

Hello everyone! I have a system of equations which I am trying to solve in order to 13 dependent variables. Yet, I am only interested in the answers which are real positives. In my code I have implemented a way to select only the answer which satisfies this constraint: Cases[ NSolve[...

Hi I have a system of ODEs of the form dx/dt = v dv/dt = a = C*f(x), where C denotes a constant and f(x) is some function of x. This system is easy to solve using (e.g.) NDSolve[x''[t] == C*f(x), x[0] == 0, x'[0] == 0}, x, {t, 0, tMax}]; I need to use the derivative of the solution x[t]...

I am checking my homework with mathematica, but sometimes when I write stuff like D[(x/((x^2 - y^2)^0.5)), y] , which is supposed to give me the partial derivative of x/((x^2 - y^2)^0.5) with respect to y, i get answer like: (1. x y)/(x^2 - y^2)^1.5 which is right, except for the...

Hi Say I solve the following differential equation in Mathematica: s = NDSolve[{y''[x] + Sin[y[x]] y[x] == 0, y[0] == 1, y'[0] == 0}, y, {x, 0, 30}] Plot[Evaluate[{y[x], y'[x], y''[x]} /. s], {x, 0, 30}, PlotStyle -> Automatic] The last line plots the solutions vs. x, but how can I...

How can I show the regular part of the solution of a differential equation, numerically solved with NDSolve, if there's a singularity on the curve ? I know how to use NDSolve and show its solution, but Mathematica gives a bad curve after some point (singularity jumping). I don't want to show...

I'm trying to plot some 3D functions in mathematica, but each time I evaluate the cell, more and more RAM gets eaten up. How do I clear the memory to keep this resonable? My PC almost crashed because I ate up all the memory. I tried ClearAll and ClearSystemCache[] and it didn't work. I'm new...

I posted this in number theory "Ramsey Primes" but I don't think this qualifies as an improper use of this forum. I need help with my code. My code for Mathematical is short so I will include it below for reference. There are some flaws. For instance the Reap/Sow function generates a list of the...

Hello everyone, I've been trying to figure out how to obtain the multiplicative inverse of an integer in Zn in Mathematica but I haven't found a way. Is there a way to do this anyone can help me with?

I'm having an output quality problem with ParametricPlot3D in Mathematica 7. I need to show a complicated curve found by numerical integration of a differential equation (using NDSolve), and export the curve's graphic (from ParametricPlot3D) to PDF, so I can use it in another application. I...

I am using Solve to try an solve this equation for u. Solve[ru(1-u/q)-(1-E^{-u^2/t}) == 0, u] However, Mathematica keeps telling me that system can't be solved with the methods used by solve. Is there another way to do it?

∂ω2 = (1-cos2(Δt)e-2γ(t))/(nTtsin2(Δt)e-2γ(t)) n,T are assumed as constants. How can I use Mathematica to find the values of Δ and t that will give the minimum values for ∂ω2 ?

Hello! I'm doing a code in Mathematica 6.0 in order to calculate a contraction of indices with the Levi-Civita tensor (in six dimensions) and an antiSymmetric tensor A[m,n,p] (it has 3 indices running from 1 to 6). For example in order to turn A into an antisymmetric tensor, I wrote something...

The program I wrote accepts a certain number between 3 and 18. Then it returns the ways this number can be obtained by throwing three dice simultaneously and adding the face values. I want to manipulate this number, :biggrin: but can't achieve it using the ordinary code of manipulation...

This can be very useful, so I thought i'd share. If you edit the > Wolfram Research\Mathematica\8.0\SystemFiles\FrontEnd\TextResources\Windows\MenuSetup.tr file you can make Strl+Shift+C copy not plain but in LateX format. Very useful. Look for the line in the file that says "&LaTeX"...

Hi, I have a whole bunch of data (Arrays of the form H1, H2, H3 etc) that I want to crunch to create 10 more variables. I did: For[i=1,i<23,i++,{f1(i),f2(i),..,f10(i)}>>>"temp.mx"] Where fj(i)= fj(H1[[i]],H2[[i]],...), the functions are different functions of the numerical data I...

How can I plot the different phase planes for a system of ODEs in Mathematica?

I have a gamma function in the form of Gamma(s-1) where s can take only positive values. How can I plot this function for different value of s using Mathematica ?

Hi, Am plotting a graph and need to scale the axes so that i can take my range of 'x'-axis values from -1 to infinity. I shall provide script, but i am using the ParametricPlot command. ParametricPlot[tab2, {up, -1 + 10^-7, 10}, AxesLabel -> {"\[Rho]", "u'"}, PlotRange -> {{-1, 2}...

Hi All, I'm trying to solve a set of three coupled ODES. I have given initial values for all functions, and I believe I have entered in the code correctly but I still get this error telling me that the derivative operator is not the same length as the number of arguments. What does that...

How can I put a Mathematica plot in my Latex document?

Hi All, I have to solve a system of non-linear equations for a wide range of parameter space. I'm using FindRoot which is sensitive to initial conditions so I have to do it by hand and by trial and error and plotting, rather than putting the equations in a loop or in a table. So what I...

I cannot seem to make mathematica plot the following equation correctly: r[t_] = 3 Cos[t] + iSin[t]; plotbeta = PolarPlot[r[t], {t, -Pi/2, Pi/2}] I have used the capital I to no avail; I have used * to indicate multiplication. It plots the curve without a problem when I leave out the i...

Hi, I am running FindRoot on three variable system of three non-linear equations for a variety of parameters (four) and a huge range of parameter values. A simplified example is as follows: one parameter and one variable: I want to solve the equation f(x,a)==0, where 'x' is the variable...

Hello All, I would like to ask about experience in general math as well as general engineering software. At university time we used in different departments 1. Mathematica http://www.wolfram.com/ + add on http://www.fgg.uni-lj.si/Symech/ 2. Maple http://www.maplesoft.com/ + add on Mechanics of...

Hello every one, this question for a mathematics experts... Suppose we have the matrix M = \left| {\begin{array}{cccc} 9 & 6 & 0 & 1 \\ 3 & 7 & 2 & 5 \\ 1 & 0 & 2 & 8 \\ 8 & 8 & 1 & 0 \\ \end{array} } \right| and we want to print only the coordinates that equal to 0...

Hi guys, I think this is a simple question for mathematica experts. How can I maximize the extracted value from a list given a index that has to respect some constrains? For example: S = {4,2,3,5} Maximize[{Extract[S,x], x<= 3, x>=1},{x}] I would like 4 is returned instead of...

Hi guys, I am struggling again NMinimize. This is my problem: I am creating a model by using goal programming, my problem now is given a list of list i.e a matrix defined in this way S = {{5, 2, 7, 9}, {1, 2, 3, 4}, {3, 1, 2, 4}} extract from the first list {5,2,7,9} a number by...

Dear all, If someone could help me solve this mathematica NDSolve problem, that would be really nice. Here is a related, simpler problem to the one I am having. Suppose I want to solve the nonlinear ODE \left(2 r + f(r) f'(r) \right) (1 + f'(r)^2) + r f(r) f''(r) = 0 subject to the...

I'm trying to do this: Suppose I have some iterative function $x_{n+1}=\sin(x_n)$. I want to demonstrate an iteration on a plot by graphing $y=\sin(x)$ and $y=x$, then drawing lines from the graph of x to the graph of sin x, like in this page...

I think its a variation of a cosine function, but i have no idea what Does anybody have any idea?

(note for editor; this is not a homework problem, this is bred out of my desire to visualize 3space) Hello fellows, I am hoping that somebody can help me. I've asked multiple teachers and tutors, but nobody can solve my seemingly very easy problem. I am taking a course in multivariable...

hi i compile a c++ program and after compiling it gives me a txt file which contains about 50000 points. how i can plot these points in mathematica? thanks

I'm trying to build a simple function that takes 2 arguments. Basically, I want it to do this: x(n+1)=a*sin[x(n)] and generate a list of x0,x1,x2 etc. up to x(n) like NestList does, starting from x0=1.0 So I want to make a list of these iterations, where a is a constant of my choice...

I am trying to solve 0.125 + 0.5 (1-x)^3 - (12.5/y)==0 for x, when y is real and y>0. I thus want to find x= 1- 0.63 ((100-y)/y)^(1/3), so that if y=100, x=1. Mathematica's Solve yields 3 roots: sol=Solve[0.125 + 0.5 (1 - x)^3 - (12.5/y) == 0, x] Root 1: 1.+((0.+0. I) y^(1/3))/(-100.+1...

Hi! Please help the idiot In[] = D[p[x,t],x,t]/.{Derivative[n_,m_][p_][q__]->a^(n+m)} Out[] = a2 In[] = D[p[x,t],x,t]/.{Derivative[n__][p_][q__]->a^Plus[n]} Out[] = a WTF? Why not a2? In the simplest case In[] = D[p[x,t],x,t]/.{Derivative[n__][p_][q__]->Plus[n]} Out []=Sequence[1, 1] In[]...

I am trying to solve the potential barrier problem numerically in Mathematica I am giving the following command but it is showing error which i could not figure out a = 2; s = NDSolve[{y1''[x] + k1*y1[x] == 0, y2''[x] + k2*y2[x] == 0, y3''[x] + k1*y3[x] == 0}, {y1[0] == y2[0], y2[a] ==...

Hello, I'm working on this Mathematica assignment, just basic tutorial-type stuff (you can ignore the details about pyrene, not important), and the fit on this function won't converge. Someone in my class said it converged fine, so I was wondering if anyone notices any errors in my work...

Hi all, I have the following code which runs without error but gives no output. It's probably simple but I just can't see the problem. [FONT="Times New Roman"]LM={}; M[line_, cur_, lq_, ld_, k_] := For [i = 1, Length[line[[1]]], i++, Module[{m}, If[line[[1, i]] == "Q", m =...

I want to do a discrete Fourier transform of the solution I have found using NDSolve, however, because the NDSolve creates Interpolating functions rather than numbers I can't do this. Any help is appreciated. I've attatched the file I'm working with. Catrin

i want to solve a large system of coupled differential equations but i get this error NDSolve::nlnum: i attach the notebook in zip format. what is the problem? thanks

Hi everyone, Is it possible to order a list of (x,y) coordinates in Mathematica by x, then y? I currently have a number of data files in which there are 5 columns: x, y, area, circularity, radius. I would like to order the list by x and y coordinates while keeping the rows intact. Thank you

hi how can i solve a system of Integro-Differential Equations in mathematica numerically or analytically? thanks

In the pic, I wonder what Mathematica can't do. :-)