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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0
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1answer
38 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
46 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
10 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: g (m1 + 2 (m2 + md)) (b - h1 [Theta]10) + 4 kd (h1^2 [Theta]10 + h1 h2 ...
1
vote
0answers
33 views

Wolfram Mathematica: Find constants in ODE solution? [migrated]

Let's say, I have a general solution to some ODE, e.g. y(x)=x+c, and a condition y(0) = 5. I want to type in something like Solve[{y[x]=x+c, y[0] =5}, {c}] and get the value of a constant. Is there a ...
0
votes
0answers
55 views

Is there a way to rewrite integrals in Mathematica using u substitution? [migrated]

In Mathematica, can I give it an integral and a few substitution rules and have it rewrite the integral in terms of those variables?
2
votes
1answer
44 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
38 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
14 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
0answers
11 views

Mean Absolute Percentage Error with mathematica

I have problem with MAPE code in mathematica. I have a data fitted from Hidden Markov Model and I will make a code for MAPE. Can you give me a code to MAPE please?
0
votes
1answer
34 views

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

What does an output of {{}} mean in mathematica after solving a system? Best Regards
0
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2answers
181 views

Graeffe's root finding method

What are the practical applications of Graeffe's root finding method?I searched a lot but couldn't find.I found that it is used in aerodynamics and electric circuit analysis.But don't know much about ...
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
3answers
2k views

How to plot a phase portrait for this system of differential equations?

I beg your help.. I'd like the phase portrait for this system. I don't know how to use Mathematica/Matlab ... :( If anyone can make this portrait and post a print screen here, I would thank you ...
1
vote
1answer
46 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
1answer
255 views

Wolfram Mathematica - Newton Backward Interpolation?

I have the following task: Create a function (in Wolfram Mathematica), called $\mathrm{NewtonBackward}$[n_,x0_,h_,f_] which interpolates backwards the function $f(x)$ with nodes {x_i = x_0 + ...
1
vote
0answers
15 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 ...
3
votes
2answers
907 views

Compute unknown limit from known integral in Mathematica?

I have an integral $\int_a^b \! f(x) \, \mathrm{d}x = c$ where I know c and either a or b. Now I want to compute either b or a (i.e., the missing limit). How would I do that in Mathematica/Wolfram ...
0
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0answers
35 views

SAGE vs. Mathematica for Lie algebras / groups?

What math software is better for working with Lie algebras and Lie groups, SAGE or Mathematica?
-1
votes
1answer
125 views

How do you set the range for ListPlot (mathematica)

I have a large set (about 2050 values) of data that I would like to make a graph out of. The data is in two columns in Excel. I copied the first column and made the list x={0, 3.6, 7.1, 10.7...} and ...
0
votes
0answers
43 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
45 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
21 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
33 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
47 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
32 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
3
votes
7answers
214 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 ...
3
votes
4answers
78 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 ...
1
vote
1answer
24 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
35 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
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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
0
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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
60 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 ...
2
votes
1answer
56 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 ...
1
vote
1answer
28 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 $\{1,3,7,9\}$. ...
1
vote
0answers
20 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
23 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
157 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
33 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
23 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
182 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
59 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
33 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
74 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 $$ \psi={-k\over 2\pi r}\sin(\theta_0-\theta) $$ ...
0
votes
0answers
54 views

In Maple or Mathematica, syntax : Finding the fundamental sol. of the Heat eq., with Dirac-Delta initial condition

I use this question as a case example for later solving more complex equations of this type : When trying to find the fundamental solution of the Heat equation using Maple (software) , I get the ...
3
votes
1answer
105 views

Fourier series for $e^x$

I'm trying to teach myself partial differential equations from Strauss' book. I have run into a very bizarre problem - I cannot figure out what is the Fourier series of $e^x$! And not even Google has ...