For questions concerning the popular computational software program published by Wolfram Research. (Note: you are more likely to get quicker and more accurate response if you ask the question on their user forum or on the Mathematica StackExchange site.)

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0answers
8 views

RunScheduledTask outputting more data than programmed to

I'm having difficulty with RunScheduledTask. I'm working on a cooling project for a class and I am getting many more data points than I want. wig = {} RunScheduledTask[(deg = temp; AppendTo[wig, ...
-3
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0answers
19 views

copying and pasting graph with legend from Mathematica [on hold]

how to copy graph and legend from Mathematica to paste on Word? the problem I face copyng graph is pretty simple, I can copy paste graph from Mathematica to Word, but without legend. can anyone ...
0
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0answers
12 views

Closed form for a Bartlett's formula for AR(2)

Consider a stationary AR(2) process $$ Y_t=\phi_1Y_{t-1}+\phi_2Y_{t-2}+e_t $$ with $e_t$'s are i.i.d. with mean $0$ and variance $1$. Let $r_s$ be the $s$-th autocorrelation ...
-1
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0answers
48 views

Wolfram Mathematica [on hold]

Does somebody know how to write module in Wolfram Mathematica which will receive boolean function without knowing how variables it will have? Thanks.
0
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1answer
14 views

Graphing Fourier transforms on a frequency versus intensity plot (how to deal with complex numbers)

I am trying to understand how Fourier transforms are used to make HNMR plots. HNMR basically consists of hitting some molecules with some radiation and listening to the radio signal that results. ...
2
votes
1answer
26 views

Is the adjacency matrix of a given graph (OR any graphs isomorphic to a given graph) a Kronecker product, and if so what are the factors?

I have a few triangular grid graphs that I am trying to express as the direct products of smaller graphs, if possible. ...
1
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0answers
16 views

Mathematica packages for symbolic computations of Christoffel symbols and parallel transports in Riemannian geometry, [closed]

I've no knowledge in mathematica (but I do in matlab), but I'd really appreciate if someone could mention what is/are the best and easy to learn mathematica package(s) for symbolic and numerical ...
0
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2answers
61 views

Techniques to solve nonlinear first-order ODEs

I am trying to solve the following nonlinear ODE: $$\frac{dy}{dx} = \frac{1}{x(ayx-b)},$$ where $a, b$ are constants and $a>0$. Moreover, you may assume that $b \neq 0$ if necessary. This ...
10
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1answer
225 views

Twilight Zelda Guardian Puzzle : Shortest Path (UPDATE: ADDED RULES)

I'm playing a video game right now and in it is a puzzle (see here). There are solutions to solving it (see here) on the Internet, but I'd like to know if this path is the shortest path (least amount ...
-4
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0answers
27 views

interpreting wave equation using mathematica [closed]

hi can someone please help me solving this problem: Let $u(x, t)$ be a solution of a wave equation $u_{tt} − u_{xx} = 0$, $x \in (0, 2\pi)$, $t > 0$ satisfying Neumann boundary conditions $u_x(0, ...
2
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1answer
169 views

Help me understand Gröbner basis result please

I'm practicing a bit with Gröbner bases but I'm not understanding the following result I obtain from Mathematica: ...
0
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1answer
51 views

Summation giving incorrect value (I think) in Mathematica

I have the problem $\displaystyle\sum\limits_{x=2}^4 \dfrac{1}{x^2}$. I know the answer to this problem should be $\dfrac{61}{144}$. When I type the problem into Wolfram Mathematica, I get the answer ...
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0answers
53 views

What is $\int (1-e^{-x})^n dx$?

For my purposes, $n$ is a non-negative integer, and $x > 0$. I didn't know how to evaluate this integral, so I plugged it into Mathematica. It told me the solution is $(-1)^n B(e^x; -n, n+1)$ I ...
1
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0answers
36 views

Precision of starting values in FindMinimum

I am currently working on an optimization of chemical kinetic model. Starting points for FindMinimum is defined as: k10 = 2.45*10^-1 and k20 = 8.65*10^-11. The step monitor is used to show calculated ...
1
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2answers
40 views

Solving differential equations with Wolfram Mathematica

So i saw this differential equations in my textbook $\frac{{{d^4}\omega }}{{d{x^4}}} + 4{\lambda ^4}\omega = 0$ and i figured why not solve it with majestic Wolfram Mathematica, so i write this ...
1
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1answer
39 views

Dual curve of the lemniscate of Bernoulli?

Does anybody happen to know the homogeneous equation $F(u,v,w) = 0$ for the algebraic curve dual to the lemniscate of Bernoullli: $$ F(x,y,x) = (x^2 + y^2)^2 - A (x^2 -y^2)z^2 = 0?$$ I looked at the ...
0
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0answers
25 views

Sum of a Normal and a Truncated Normal distribution on Mathematica

I asked a question about the "Sum of a Normal and a Truncated Normal distribution" about 11 days ago, and someone helped me (I appreciate his\her help a lot). I tried to do same procedure as he\she ...
2
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0answers
18 views

Finding feasible solution of inequalities in math software

I have a Math problem where I have some true statements, and I want to know if there is a feasible solution to an equation. I would like to know how to do that in either Matlab or Mathematica. The ...
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0answers
13 views

Creating a graph with linear regression together with error bar using mathematica

Can anyone help me with incorporating error bars (standard deviation) into a graph showing linear regression?
0
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0answers
28 views

Importing microsoft excel data to Mathematica

I used the import function in Mathematica to import an excel file and while Mathematica did perform that, the data in the cells in excel appear in curly brackets in Mathematica. What can I do to ...
0
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0answers
13 views

FindRoot[rhs==lhs, {X,x1,x2}] Vs. FindRoot[rhs==lhs, {X,x1}]

What is the difference between these two commands: FindRoot[rhs==lhs, {x,x1,x2}] and FindRoot[rhs==lhs,{x,x1}] They give me completely different solutions. Thanks
0
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0answers
21 views

Irregular Implicit Plot in Mathematica

While studying the implicit relation $ y=x\tan(a\sqrt{x^2+y^2}+b)+c$ I came across some spurious looking parts in the graph WolframAlpha produces. These are jagged circles with radii that appears to ...
0
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0answers
19 views

How do I compute uncertainties in the positions transformed using Helmert transformation?

I am familiar with Python, MATLAB and Mathematica. My data is given by Cartesian coordinates (positions in X,Y,Z (meters), standard deviations XX, YY, ZZ (meters) and a correlation matrix (XY, YZ, ...
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0answers
14 views

Solve multivariate exponential inequality via program

I am trying to solve a complicated exponential inequality with six parameters and one variable t. This can't be done with mathematica command "Solve, Reduce or FindInstance". Is there any other ...
0
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0answers
18 views

Getting a part of a matrix in mathematica

I was trying to get an element of a matrix, and use in further computation of my program. Problem was that its not reading the value unless and until I specify it again. My code is: ...
10
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4answers
275 views

A numerical evaluation of $\sum_{n=1}^{\infty}(-1)^{\frac{n(n+1)}{2}}\frac1{n!}\int_0^1x^{(n)} dx$

I would like to obtain a numerical evaluation of the series $$S=\sum_{n=1}^{\infty}(-1)^{\frac{n(n+1)}{2}}\frac1{n!}\int_0^1x(x+1)\cdots(x+n-1)\: dx$$ to five significant digits. I've used ...
1
vote
1answer
73 views

Inverse gradient as line integral in Mathematica

I found a nice paper about inverse vector operators here. I have successfully defined a Mathematica function for inverse curl and inverse divergence, however I can't figure out how to do inverse ...
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1answer
82 views

How does Matlab, Maple, etc…solve algebraic and differential equations internally?

I would be very interested finding out how does Matlab, Maple, etc…solve algebraic and differential equations internally? Anyone know how they do it?
4
votes
2answers
141 views

How to actually use the Weierstrass-Enneper parameterization to draw a minimal surface?

I'm interested in drawing (with Mathematica for example) the generalized Scherk saddle tower with threefold symmetry, a shape that I find very attractive. In an article (see here) I found the ...
3
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0answers
54 views

The mathematics of anaglyph images

Note: I'm not quite sure whether this question properly belongs to the Mathematica or to the mathematics Stack Exchange. But because my question mainly concerns general mathematical principles rather ...
0
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1answer
42 views

Minimizing a function in Mathematica

Edit: I simplified the function using $\textbf{Simplify[...]}$ How can I minimize this function of $x$, where $l$ is a positive constant? $$\frac{1}{2} \sqrt{\frac{x}{l}+\frac{l}{x}+4 x^2-2}$$ ...
2
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1answer
76 views

I can't solve this integral in Mathematica

I want to calculate the following integral in Mathematica 10 $$f(x) = ...
0
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0answers
29 views

Pade_Approximant in Mathematica

I want to calculate Pade_Approximant for exponential function in power of 3. I wrote this code but it seems that the answer isn't true. please help me In[131]:= PadeApproximant[Exp[x^3], {x, 0, {3, ...
1
vote
1answer
85 views

Torricelli's Law with a Sphere (Ignore Mathematica part, already solved)

Edit 1: According to this PDF, second page. The differential equation for a hemisphere becomes $$(r^2h-h^2) h' = -a^2\sqrt{2gh}$$ This differs from the equation I got, which looks like: ...
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0answers
18 views

Proving susceptibility in Lorentz Model satisy Kramers-Kronig relations

My instructor asked me to prove that the real and imaginary parts of the electric susceptibility derived from Lorentz Model satisfy the Kramers-Kronig relations using the residue theorem. The problem ...
0
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0answers
29 views

Simplifying expressions or expressing it in more known functions

In mathematica I asked FullSimplify[ DSolve[{y''[x] + 1/x y'[x] + y[x] (1 - 1/x^2) == x BesselJ[1, x]}, y[x], x]] and it gave as the answer {{y[x] -> BesselJ[1, x] C[1] + ...
0
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0answers
32 views

Ritz Approximation

I have the following problem: $1/r * d/dr(r*d \theta/dr) - N_1(\theta-\theta_a)^2 -N_2(\theta^4-\theta_a~^4)=0$ where $N_1, N_2,$ and $\theta_a$ are constants Subject to $r=1$ : $\theta=1$ $r=L$ ...
0
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0answers
37 views

Fifth order BVP using Daftardar Jafari method-Research paper example query?

Please check the research paper regarding numerical solution of non linear 5th and 6th order BVP using Daftardar Jafari Method (section 6: numerical results, example 1) ...
1
vote
1answer
34 views

Scaling axis on Mathematica's plots

I'm trying to get the plot below only I want the ratio y:x to be 1:1 instead of 2:1. I want the ellipse to look tall and slim instead of short and fat. Here's the code line if you want to copy and ...
1
vote
1answer
175 views

How do I plot normal distribution

If I know the range (1-24) and know the area (X), how can I plot a normal distribution so that the curve has area X?
2
votes
1answer
22 views

Generating a data set that approximates another given random variable

One of the question my friend was asked in technical interview : The probability density function for a normal random variable with μ = 0.6 and σ = 0.7:​ Below is the code to generate the ...
1
vote
1answer
37 views

Expected number of passengers for the flight

One of the interview questions that I was asked was : The small commuter plane has 30 seats. The probability that any particular passenger will not show up for a flight is 0.1, independent of ...
1
vote
2answers
79 views

How to plot a phase potrait of a system of ODEs (in Mathematica)

I am asked to use mathematica to plot the fixed-points of the following system $$ \frac{dN}{dt} = -\gamma N \left( 1 - \left( \beta M + N\right) \right) $$ $$\frac{dM}{dt} = M \left( 1 - \left( ...
0
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1answer
27 views

Exponential Distribution - Generate a fairly hefty data set X that is approximately exponentially distributed with μ = 0.7.

I encountered a question in one of the books, which asked to generate a fairly hefty data set X that is approximately exponentially distributed with μ = 0.7. I can do it for approximately normally ...
1
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0answers
38 views

ODE with Reflection

Some Background: I come from a computer science background and differential equations was not part of my course work. I'm still in contact with my professor that I ...
0
votes
1answer
294 views

how to substitute a variable by a number in wolframalpha

Peace be upon you, How can I compute \begin{align*} sin'(0) \end{align*} in Wolframalpha? like what in Maple, I try subs(diff(sin(x),x),x=0) But it doesn't ...
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0answers
18 views

Determining the sign of a function containing ratio

Problem We want to know for which values of $x,y,z,w$ the function $\sigma$ is positive or negative: \begin{equation} \sigma = \frac{A}{A^2-B^2}, \end{equation} where \begin{eqnarray} A & = ...
0
votes
1answer
23 views

Mathematica Cubic Polynomial

I am interested to find the roots of a cubic polynomial f(r)=r^2 - 2 r + Q^2 - [Alpha] r^3. \Alpha is positive real number hare, Q is real. I am interested in 2 complex roots and third root to be ...
1
vote
1answer
47 views

Analytical solution for bound state energies of infinite well

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: ...
3
votes
1answer
77 views

Integration: $\frac{2}{\pi} \int_0^\pi \frac{\sin(nx)}{10}x(\pi-x) \mathrm{d}x$ Can someone matlab/mathematica/maple it for me?

I want to compute $\frac{2}{\pi} \int_0^\pi \frac{\sin(nx)}{10}x(\pi-x) \mathrm{d}x$, where $n=1,2,3,4,\dots$ I worked this by hand and got the result: $-\frac{4\cos(nx)}{10n^3\pi}$ To check my ...