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.)

learn more… | top users | synonyms

0
votes
1answer
14 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
23 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: ...
0
votes
0answers
24 views

CDF of ratio of Gamma distribution with different parameters

Let $X$ be gamma distributed random variable with parameters $a$ and $b$. Let $W$ be gamma distributed random variable with parameters $c$ and $d$, such that \begin{equation} f_X(x) = ...
-1
votes
0answers
17 views

How to fix the order of AxesLabel in Mathematica 7.0 plot [migrated]

One of the AxesLabel is "$:\text{log}|\Phi8b(u)|\color{Red}{\text{Red}}$". Question: How to make it like: "$\color{Red}{\text{Red}}:\text{log}|\Phi8b(u)|$"?. The Mathematica command is: ...
3
votes
1answer
55 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 ...
1
vote
1answer
62 views

Mathematica Question regarding NSolve

I'm trying to solve for 2-cycles for the equation $$x=xe^{r[1-x]}$$ using Mathematica. I've tried using NSolve, FindRoot, and Solve. When I use NSolve I input it as $$\textrm{NSolve}[xe^{r[1 - xe^{r[1 ...
0
votes
0answers
17 views

Plotting Dirichlet Series $L_{\tau}(s)$ related to Ramanujan tau function in Mathematica

According to wikipedia, Ramanujan tau function $\tau:\mathbb{N}\to\mathbb{Z}$ is defined by equating the coefficients of the power series on both sides of the identity: ...
0
votes
0answers
11 views

Introduce break after operation

I have made a function to select manually feature points in two images. However I can keep clicking endless because I don't have a limit for feature points. I now want to introduce a kind of button on ...
1
vote
1answer
61 views

Mathematica Giving Me Trouble

I'm new to mathematica and am just learning the basics. I've run into a few things that I can't figure out. The first is this: "Number 11" $$r[t\_] := \{(1/3)*(t^3), 0.5 * t^2, t\}$$ (*Unit ...
1
vote
1answer
27 views

In Mathematica is it possible to define the plot range by an inequality?

For example, like Plot[Sin[x], {x, Sin[x]<0.5}] The above line is not working. I want to know if this idea is possible in Mathematica. Thank you!
0
votes
1answer
49 views

Best program for multiplying many multivariable polynomials

I want to make a table with two columns: The first column will consist of many(possibly hundreds) of polynomials in two variables. The second column will be a function applied to all of the ...
2
votes
0answers
49 views

Algorithm to find the “optimal” path in a given graph

Assume that $G=(V,E)$ is an undirected connected graph and that $H: V \to \mathbb R$ is a function that assign at each vertex $v \in V$ its height $H(v)$. Think of the pair $(G,H)$ as an energy ...
1
vote
0answers
15 views

Assigning a variable as constant and find out the minimum value

I have got a problem in assigning a variable as constant and solving a equations for minimum value. These are my equations: kd (2 h2 Cos[[Theta]2] - b2 Sin[[Theta]2]) (b1 - (b1 + b2) ...
2
votes
1answer
49 views

contour plot using Mathematica

I want do a contour plot in Mathematica as: ContourPlot[{Re[F[5/4, x + I y]] == 0, Im[F[5/4, x + I y]] == 0}, {x, -20, 20}, {y, -20, 20}, PlotPoints -> 100]; where function F[b,z] is defined ...
0
votes
1answer
39 views

Help with Complicated Definite Integral

I am trying to find the integral of the following expression, with respect to $t$ from $0$ to infinity: $$\frac{e^{-a g t} \left(b-(g-1) \left(\text{H0} \left(e^{a t (-b+g- ...
1
vote
0answers
19 views

Is there any interactive spline fitting software?

I'd like to know if there's any software (freeware) for interactive data interpolation. What I want is to be able to visualize my data on an XY plot and drag the points to see how it affects the ...
0
votes
1answer
36 views

Mathematica Output Meaning ({{}}) [closed]

What does an output of {{}} mean in mathematica after solving a system? Best Regards
0
votes
1answer
28 views

Trying to calculate 5 simultanious equations in Mathematica

$\def\1{x_1}\def\2{x_2}\def\3{x_3}\def\f{f(\1,\2,\3)}\def\bs{\bigskip}\def\b{\begin{pmatrix}}\def\e{ ...
1
vote
1answer
53 views

Why is a complex number plus infinity equal to infinity?

Why is $$2 + 3 i + \infty = \infty$$ according to Mathematica and Wolfram Alpha? Shouldn't it be: $$2 + 3 i + \infty = \infty + 3 i$$ ? After all: $$2 + 3 i + 10 = 12 + 3 i$$ and not: $$2 + 3 i ...
1
vote
0answers
17 views

Computer Code Friendly Books On Differential Equations?

When I need a differential equation for this or that application I generally search (by hand) through old paper and ink books written by mechanical or electronical (electrical) engineers. Sometimes my ...
0
votes
0answers
50 views

SAGE vs. Mathematica for Lie algebras / groups?

What math software is better for working with Lie algebras and Lie groups, SAGE or Mathematica?
0
votes
0answers
46 views

Finding circle which touches two functions

I wasn't sure whether my issue is with my Mathematica code or the actual way I am trying to figure out my problem so if it is a Mathematica issue I can ask it on that stack exchange. Firstly I have ...
0
votes
0answers
32 views

traingular matrix

I am not much in to the matrices. so I am sorry if I can not put forward the question properly. Assume $G_{n\times n}$ is a rank $n$ matrix (Indeed $G$ is the generator matrix of a lattice). I need ...
2
votes
2answers
47 views

Help finding a summation using CAS

While approximating an integral by midpoint rule, I ended up with $$\iint_R f(x, y)\hspace{1mm}dA\approx \dfrac{1}{n^2}\sum_{i=0}^{n-1}\sum_{j=0}^{n-1} f\left[\dfrac{1}{2n}+\dfrac{i}{n},\hspace{3mm} ...
0
votes
0answers
23 views

Need Suggestion: good CAD tool to solve inequality

I want to solve the inequality: $f(x,y,z,w)-g(x,y,z,w)>0$ $s.t. $ $ x>0$, $0<y<1$, $ z>0$ , $ 0<=w<=1$, $f(x,y,z,w)>1,$ $g(x,y,z,w)>1$ where $f$ and ...
0
votes
0answers
41 views

Implementing formula correctly in matlab for neuroscience: total soma membrane potential?

Please help me to understand: am I correctly implementing a total soma membrane potential (TSMP) equation in Matlab? Due to being a new member I need to use this list link to refer to the links ...
1
vote
1answer
53 views

Solution to second order differential equation

I'm reading a paper in which the authors solve the following equation: $\frac{d^{2}}{dz^{2}}\hat{p}$($\bf{q}$$,z)$-$q^{2}\hat{p}$($\bf{q}$$,z)$-$\frac{iq_{y}}{(2\pi)^{2}}\delta(z-z_{2})$=0 here ...
-1
votes
1answer
33 views

poisitive definite matrix imply matrix of full rank? [closed]

Is a positive definite matrix always of full rank? while is given that the characteristic roots are pisitive
1
vote
1answer
29 views

Conversion of Hypergeometric functions from Maple to Mathematica

After a calculation I found in Maple an expression of the kind: $$f(x)=hypergeom\left(\left[\dfrac{a}{b},1\right],\left[c,d\right],h\right)$$ What is the equivalent notation in Mathematica which I ...
0
votes
0answers
36 views

Solving partial differential equation with mathematica.

I am trying to solve the heat equation in cylindrical coordinate. The object of inspection is a thick ring with height $\{z_0,z_L\}$ and radii $\{r_1,r_2\}$ within a heat generating environment. I ...
0
votes
0answers
38 views

complex ordinary differential equation of a real variable

reading a paper i have found the following differential equation: f''[z] - (q^2)*f[z] == i*DiracDelta[z] here f[z] is a complex function of the real variable z ...
0
votes
0answers
26 views

How to interpolate and obtain this graph?

I was interpolating with software mathematica v9, but how can I obtain a curve similar to this?, in a easy way
3
votes
4answers
79 views

indefinite integral computation $dx/(e^{-x}-x)$

Hi i'm trying to carry out the following indefinite integral: $$\int \frac{1}{e^{-q} - q} \, dq$$ mathematica is not helping me, and i think it is not solvable by substitution method. any idea on ...
0
votes
0answers
26 views

Splitting a list into two lists, depending on a condition.

So I have this list of n real numbers called A, which is sorted least to greatest. Let B be a list of n real numbers with NormalDistribution[]. IF A+B = Sort[A+B], then we keep it, and if A+B != ...
0
votes
0answers
61 views

Mathematica Integrate gives back the integrand

i'm trying to Integrate the following function: (q (1 + q) - E^-q Sinh[q])/(-q + Cosh[q] Sinh[q]) - ( 2 q Tanh[q])/(-q + Cosh[q] Sinh[q]) I already solved ...
1
vote
1answer
29 views

Reduced Residue System in Mathematica

How can I create the standard reduced residue system modulo $m$ in Mathematica for a given positive integer $m$? For example, if I input $10$, I would like it to give me the list $\{1,3,7,9\}$. ...
2
votes
1answer
58 views

Fourier series of oscillation in form $\cos(2 \pi \frac{k}{T}+\phi)$

I would like to calculate the fourier coefficients of $\cos(2 \pi \frac{k}{T}+\phi)$ where $T \in \mathbb{N}$ is the period and is arbitrary but fixed, $k \in [1, N-1]$ is the number of oscillations ...
3
votes
7answers
248 views

Best Math Plotting Software for Electrical Engineering

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 ...
1
vote
0answers
22 views

Can nodes of Gaussian quadrature shift range?

I used my Python program to generate Gaussian's nodes and their weights. My python program could generate nodes as default in rage of (-1, 1). And my friend used Mathematica to generate them also but ...
0
votes
1answer
19 views

Filling between two curves in Mathematica [closed]

I want to fill region between 2 curves, but in mathematica 8.0 FilledListPlot[list1, list2, Fills -> {RGBColor[f, f, f]}] doesn't work. can someone help me? Thx
6
votes
1answer
153 views

Odd Mathematica series result

I asked Mathematica to evaluate $$\sum_{i=1}^{\infty} \cos(i a)\cos(i b)$$ where $a$ and $b$ are unspecified real numbers, and it told me the answer was simply $-\frac{1}{2}$. This is clearly wrong, ...
2
votes
0answers
32 views

Algorithm for FindSequenceFunction

What algorithm might Mathematica be using to compute FindSequenceFunction? Does anybody know if there is any online material on this topic?
3
votes
4answers
158 views

A limit question (JEE $2014$)

The following is a JEE (A national level entrance test) question: Find the largest value of the non-negative integer ( a ) for which: $$ \displaystyle \lim_{x \to 1} \left( \dfrac{-ax + \sin(x-1) + ...
0
votes
0answers
34 views

list of all irreducible polynomials of degree at most n over the field Z/PZ.

I am trying to write a mathematica coding to give me the list of all irreducible polynomials of degree at most n over the field Z/PZ. I started by defining univariate polynomials of the form p = a_0 + ...
1
vote
0answers
24 views

Two factor ANOVA discrepancy with Mathematica

I have a set of two factor data I am doing ANOVA analysis on, both with Mathematica's package and manually (because learning!) Using one set of example data (found here 1) both my manual calculation ...
0
votes
2answers
183 views

Is this computation erroneous?

The solution to $\lim_{n\to\infty}\frac{n^{100}}{2^{n/100}}$ should be $\infty$ because $n^{100}$ grows much faster than $2^{n/100}$ But if you input ...
4
votes
1answer
62 views

Finding the period of the solution to $y'(x) = y(x) \cdot cos(x + y(x))$ with Fourier transform; how to interpret complex result?

A question elsewhere on this site asks about detecting the frequency of oscillations in a system defined by differential equations. The equation is $y'(x) = y(x) \cdot cos(x + y(x))$. The solution ...
1
vote
0answers
34 views

How to evaluate Bessel functions $K_{i x+\frac{9}{4}}(2\pi)+K_{i x-\frac{9}{4}}(2\pi)$ with $x>1.5*10^8$ in Mathematica 7?

I am trying to evaluate Bessel functions $K_{i x+\frac{9}{4}}(2\pi)+K_{i x-\frac{9}{4}}(2\pi)$ with $x>1.5*10^8$ in Mathematica 7. This function is the first Polya approximation to Riemann ...
0
votes
1answer
83 views

Partition a set into n subsets with elements with sum equal to m

For example, given the set $a_n = \frac{n}{20}$ for $\,n \in \{1,\,2,\,\dots,\,19\}$, I would like to get all possible partitions of this set in 4 subsets such that the sum of their elements is always ...
1
vote
0answers
39 views

Plotting in Mathematica

I'm new to mathematica. How would I plot the following functions in the polar complex plane? $$ \phi={-k\over 2\pi r}\cos(\theta_0-\theta) $$ and $$ \psi={-k\over 2\pi r}\sin(\theta_0-\theta) $$ ...