Mathematica Definition and 1000 Threads

a\text{''}[t]+B[t]*a'[t]-A[t]*a[t]==0 a[0] = 10^-9 a'[0] = 0 a[t] = ? The coefficients A and B are variable over time. I HAVE solved (experimental and theoretical values) for the values of A and B over the time interval of interest! I attempted to solve for a[t] using NDSolve as one...

I want to plot this polynomial: Q10[x_] := c* (1 - (t - x)^2)^10 I defined variable 't' in f(t) and 'x' in the polynomial Q10[x]. how can I plot this polynomials with variebles x and t? the range-interval will be (for both x and t): [0,1]. can you write the code please... Thanks... Edit...

Hi all, Kinda new to Mathematica. I have evaluated a function describing a sphere's (or just circle for simplicity) radius over time. I have made a Table of values for the radius over a given time interval, and am able to plot the radius vs time. How can I make an animated 3D plot of...

Hi guys I am trying to plot a function with respect to T, but I want to rescale my axis. For example my range right now shows 0, 10, 20, 30. But I want it to show 0, 1, 2, 3 and so that I can then put an x-axis label of T/10. Can anyone help?

Just wonder if anyone in our little community is using Mathematica on Linux or Unbuntu. I have another license to use and a box with Unbuntu.

Hello everyone, I have a list, let's call it L1, of length N. Each element of this list is a square matrix. I would like to : 1/ Apply MatrixExp[] to each element of L1 (I know how to do that) 2/ Multiply each element of the subsequent list _in an ordred fashion_ i.e. from element N to...

Hi guys, I am writing a code for mathematica... I have two lists for t(time) and T(temperature) such that t=(t1,t2,t3...tn) and T=(T1,T2,T3,T4,T5...Tn) I have a formula that needs me to correspond the values in the two lists...which means... T1 is the value recorded at t1... any...

Hi folks, i just want to call different functions which are solutions of set of rate equations from s= NDSolve in a loop to calculate something. For[k = 0, k < 27, k++, x[k] = N#[time] /. s; ] # is just an arbitrary sign. i just want to replace # with k so i call N0[time]...

OK, here's a problem I'm trying to solve for my work. Given a set of n points {(x1, y1), (x2, y2), ... (xn, yn)} I need to obtain a linear function f from the broken line which connects all these points, so that I can the value of f at any point. I need to do this for two sets of points, i.e...

Hello, I have a problem with numerical solution of the system of ODE's (geodesic eqs.) in Mathematica. The only relevant command I have found is NDSolve. It works perfectly, unless my equations contain functions which are again computed using numerical methods. Simple example illustrating...

I use NMinimize to optimize a likelihood function. The number of parameters included depends on the dimensions of a vector I pass. I would like to have Mathematica check the dimensions of the vector, declare the correct number of parameters for me, and then solve for them. Right now, I have...

Mathematica: In[1]:= x = {(u + 2 v)/3, (u - v)/3, w}; D[x[u], u] Out[1]= {1/3, 1/3, 0}[u] + {(u + 2 v)/3, (u - v)/3, w}’[u] Why does it do this? Wolfram Alpha gives the answer I expected...

I want to produce a bifurcation diagram using mathematica to represent equilibrium points of p1 using the data obtained from the following code, where pn1, pn2, pn3 are recrusion exquations. i.e. x-axis will be the paramter t (ranging from 0-0.3) and y-axis will be the values of p1 this code...

Hi everybody. I have an impicit function that I want to solve numerically in mathematica it looks like: f[x] == b1 \!\( \*SubsuperscriptBox[\(\[Integral]\), \(0\), \(L\)]\(c[ x, \[Alpha]] f[\[Alpha]] SuperscriptBox[\(E\), \(-\( \*SubsuperscriptBox[\(\[Integral]\), \(0\)...

Hi, I was solving the following second order ODE: http://www.texify.com/img/%5CLARGE%5C%21x%5E2%20y%5E%27%27-5xy%5E%27%2B5y%3Dx%5E6%20sinx.gif I used variation of parameters and found this solution...

Homework Statement Graph in Mathematica to solve d^2theta/dt^2 + g/lsin(theta)= 0 Show a graph of period vs. Theta not. Homework Equations The Attempt at a Solution I am not very experienced with entering information into mathematica. I am aware that the manipulate plot...

Homework Statement A)Show that for a non-frictional, simple linear pendulum (Sin(theta) ~ theta) the total energy of the pendulum (K + U) or kinetic plus potential is given by E = (1/2) m l^2 (d(theta)/dt)^2 + (1/2) mgl (theta)^2 and therefor E = (1/2) mgl(theta0)^2 theta0 =...

Using the following code in mathematica: << DiscreteMath`Combinatorica` ShowGraph[TetrahedralGraph] Produces a regular Tetrahedral Graph. I would like to show data points on this tetrahedral graph with specific coordinates relating to the four points of the tetrahedron. Is this...

I have a plot of radius and temperature. I want to plot it in 3D by rotating it about the origin to produce a 3D plot. I can not figure out how to do this in Mathematica without doing it by hand and then plugging it into the Plot3D function. Any advice would be greatly appreciated. The...

Hi everyone. Hopefully this is easy to solve. I have large amounts of mined data that have differing levels of precision. I want to do analysis of: 1) number of decimal places present 2) significant figure error intervals based on the precision (for instance, 0.003 could have been...

What is Mathematica command for differential equation y''+2y'+5y=(sinx)*(e^x)?

I want to make a tetrahedron in mathematica. For example, suppose: {a = 0.2, b = 0.5, c = 0.1, d = 0.3} {a = 0.1, b = 0.2, c = 0.4, d = 0.3} {a = 0.4, b = 0.3, c = 0.2, d = 0.1} {a = 0.6, b = 0.2, c = 0.1, d = 0.1} and I want a tetrahedrom so that the four points are a, b, c and d -...

Good day to all, I am stuck with this. I am trying to construct a matrices with this properties... if n = 8, suppose the matrix with size 1 by 8 become [16 -16 16 -16 16 -16 16 -16] if n the matrix become [2n -2n 2n -2n 2n -2n 2n -2n ] with size 1 by n I do appreciate if someone...

i try run my program for NMinimize.it took a long time to solve.What is the problem of my coding?

edit: Forgot to add Mathematica in the title. Sorry! Hi everyone. I mined a lot of data and want to analyze it in Mathematica. The data is of the form {{x11, y11, x12, y11, x13, y13},{x21, y21, x22, y22}...} meaning that each set of x,y pairs is not necessarily the same size...

Hello, my name is Maciek, and I come write from Poland. I have big problem with Mathematica. The Program does not work. I can not put the coursor in a notebook, can not do any calculatins. Uninstall and install did not help. Mayby someone of You had simillar problem. Thank You for help!

I am wondering if anyone can tell me how to get Mathematica to recognize the product of two variables so that I can do things like take limits. For example, if I had a function F[x] = x*(R*W)^2 + 4*x and I want Mathematica to take the limit as (R*W)->0, how can this be done? I realize this...

Is there a way to animate and export a 3D plot such that it rotates about the z axis automatically? A friend is doing a presentation and I'd like to make some animated files of the 3D plots we've been making to include in a power-point. I've looked through help files and some google searches...

Hi, I have a system of ODE's for which I want to compute points for a Poincaré section. I used NDSolve and EventHandler in Mathematica but EventHandler appears rather messy/limited for my condition: Suppose I want to save 4 iterations of a Poincaré map and then abort integration imediately...

I'd like to make a single 3D graph that contains a scatter plot and a plane. Ideally I'd like to import the data for the point from an excel file, but if I have to punch it in, I can find a few hours to kill. Anyway, can anyone help me with the code for this? I can get a 3D scatter plot where...

I'm new to Mathematica. I used it to integrate the scalar field f:\mathbb{R}^3 \to \mathbb{R} \; \bigg| \;f(x,y,x)=z^2 over the top half of a unit sphere centered on the origin, paramaterising this surface with \phi: \mathbb{R}^2 \rightarrow \mathbb{R}^3 \; \bigg| \; \phi(r,\theta)=(r...

Assuming[a>0 && b>0 && c>0, FullSimplify[a+Sqrt[b+c]-Sqrt[a^2+b+c+2 a Sqrt[b+c]]]] does not simplify it to zero. Although output of FullSimplify[a+Sqrt[b+c]-Sqrt[a^2+b+c+2 a Sqrt[b+c]]==0] is true, even without any assumptions. Can anyone please resolve this puzzle...Thanks

I have some data I imported into Mathematica. It has three columns. I want to plot col1 vs. col2, col2 vs. col3, and col1 vs. col3. I started out doing this Flatten[Partition[data, 3]] to get one long list. I'm kind of lost. Any help is appreciated!

Hi, I'm trying to save (into a file) definitions of some variables which are of the form Subscript[A,1], Subscript[A,2],... where the subscript is used as an index for the variable. When using the Save command I obtain the error Save::sym: Argument A1 at position 2 is expected to be a...

I have a user-defined function that doesn't seem to work with NMinimum, FindMinimum, or any of the other optimization commands. I think this is due to the fact that the function uses elliptic integrals and matricies to obtain an output. It has multiple variables, but I want to keep them all...

[FONT="Georgia"]I'm trying to compute the eigenvalues for a 32x32 symbolic matrix (with one variable) in Mathematica. I get the following error: [SIZE="1"][SIZE="3"]Eigenvalues::eival: Unable to find all roots of the characteristic \ polynomial. >> [FONT="Georgia"]What could be a possible...

Hey I'm wondering if anyone has ever heard or knows of a touch screen program that would maybe use something similar to the Mathematica engine. I have seen some handheld touch screen computers for very cheap. It would be really useful(and just plain awesome) to be able to create equations and...

I am attempting to program Mathematica to multiply the square free terms of an integer. Basically say we are looking at 252, its prime factors are 2^2*3^2*7. So what I want to do is have Mathematica return to me just 2*3*7 when I enter 252. So I have this S := FactorInteger[252]...

Hi everyone, I am trying to solve this complicated two simultaneous equations, and it has been taking more than 2 hours to solve .. and it is still running... can anyone tell me what is wrong .. thanks Solve[{((((1 - xr)/xr)^(1/2) (M2^2 xr - 1)/( 1 + (gam + 1)/2 M2^2 - M2^2 xr)) -...

Hi, I have always been in love with computers and started programing early. When I started my studies in Physics like three years ago, people often recommended Matlab. I spent a lot of my spare time playing with it (e.g. solving ODEs, plotting solution, animating, plotting and evaluating...

hi, I have two equations that I have used the Solve function in Mathematica to solve for A in both equations What I am having trouble with is trying to equate the results and solving for another variable J automatically Basically this is what I want to do: Solve[Eqn1, A] It gives {{A ->...

Hi, Guys Can someone help me about this question? I am trying to use Mathematica to plot all the functions: y=k-x/k for all -10<k<10 with interval of 0.1 what I wrote is like this: Plot[Table[k-x/k,{k,-10,10,0.1}],{x,-10,10}] However, because the function doesn't have meaning when k=0...

Hello again. Sorry for all the posts. I have a histogram of frequencies in Mathematica and the intervals on the x-axis are predefined and kind of unrepresentative. I changed the bin number (with 'Histogram[mydata, binnumber]') but I can't seem to find anything on the internet about changing...

I have imported a list of data of this kind 4.447E-02 1.620E-02 1.281E-02 2.585E-02 3.676E-02 1.232E-01 7.635E-02 1.756E-02 1.142E-02 3.676E-02 and it goes on, 2000-ish numbers. I try to do a ParetoPlot and all I get is an empty plot. I have loaded the Statistic Plot Package. Is it...

Hello everybody! I've got a Mathematica problem that I've been working on for a while but can't seem to solve. My code is pretty involved, so I'll simplify the dilemma for you. F1 := Function[{x,m,b}, y = m*x+b; Print[y] ] I have a function called F1. If I call it like...

Hello everyone, I am working on trying to model a bouncing light ray between two curves, and I would like to model it in Mathematica. However, I do not know what syntax or how to go about typing the code in. I tried to find examples on the Mathematica Documentation Centre but the examples...

Does anyone know how to test if some graph contains an Eulerian path in Wolfram Mathematica? I don't need the actual path, I just need to know if one exists.

Hi folks, I'm trying to graph something in Mathematica, and honestly don't know where to start. Imagine you have a rectangle in the x,z plane of a 3D space. Now, twist one end of the rectange so it's parallel to the y axis. The opposite end remains parallel to the x axis. Between the two...

Hey folks :smile: Clearly there is a better way to do this. It should be clear that I want n to take on the value of alpha and not the expression "alpha --> value" What I really want to do is this: Evaluate the value of alpha at each value of i and then output the value of i in one...

Hello, 1) I am trying trying to simulate a laser scattering experiment in Mathematica. So the first trouble I have is how to define a set of 3D points. I did this program in C++ like this: for (int i=0; i<3; i++) { pyr[0].point[0][i]=0; } for (int a=1; a<3; a++) { for (int b=0; b<3...