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

2
votes
1answer
304 views

Automatic calculation of the intersection of discrete curves

first of all, let me apologize for a poor math-english translation, I'll try my very best. I have the following situation: I have over 16.000 data files which I generated from a biometric ...
1
vote
0answers
298 views

$\int^{\infty}_{0}x^{r +s- 1}(1 + x)^{-s}(1 + x^2)^{-\frac{rm}{2}}dx$

I'm trying to solve the integral $\int^{\infty}_{0}x^{r +s- 1}(1 + x)^{-s}(1 + x^2)^{-\frac{rm}{2}}dx$, where $s$, $r$ and $m$>1 are positive integers. My question is whether a closed form ...
1
vote
2answers
120 views

Unexpected results when integrating definite integral with variable bounds

When I plug something like this into Mathematica: $$\int_0^{x^2-1} k y \, dy$$ I get exactly what I would expect: $$\frac{k}2 (x^2-1)^2 $$ However, when I change my bounds ever so slightly, from ...
1
vote
1answer
127 views

Solve autonomous ODE with Mathematica

I'm given a problem with the ODE y'[x]=y[x]*Sqrt[4-2y[x]] I've tried DSolve[{w'[x] == w[x]*Sqrt[4 - 2*w[x]]}, w[x], x] which gives me {{w[x] -> -2 (-1 + Tanh[1/2 (-2 x - Sqrt[2] C[1])]^2)}} but ...
0
votes
0answers
173 views

A (contour?) integration (even if by using Mathematica!)

I need to be able to calculate integrals of this type where the sum over $R$ is the sum over representations of a Lie group $G$ on whom $dU$ is the Haar measure and $\chi _ R ()$ is the character of ...
-2
votes
5answers
481 views

Cryptography in Maple and Mathematica

Is Maple or Mathematica preffered over the other for Cryptography/Number Theory? What are the advantages for each in terms of this area of mathematics? Also could someone compare and contrast ...
2
votes
3answers
50 views

A way to identify a unique number '$a_1$' has performed operations on '$x$'

The problem I have is bit vague, so I will try to explain as best as I can. Suppose we have a base number '$x$' and a set of unique number $'a_1', 'a_2', 'a_3', 'a_4'$ and so on Now $a_1$ perform ...
1
vote
1answer
769 views

Existence of non-trivial solution of Sylvester equation.

I'm trying to solve a special case of Sylvester equation in my case it looks like $$A*X=X*B$$ so it can be written in form $$A*X+X*(-B)=C$$ where C consist of all 0 items. I tried to solve it in ...
6
votes
3answers
221 views

Computer Algebra Systems which implement Cylindrical Algebraic Decomposition

My understanding is that Mathematica's Reduce function is based on Cylindrical Algebraic Decomposition (CAD). The only other system I've seen which implements CAD ...
3
votes
1answer
541 views

Solution to a second order semilinear elliptic PDE

I am trying to find a solution (if one exists) to this PDE where (r,z) are cylindrical coordinates. $$u_{rr}+u_{zz}+u_{r}/r-u/r^2 = u^2u_{r}/r+u(u_{r})^2+u(u_z)^2$$ u is a dimensionless function ...
0
votes
1answer
130 views

Using a Bivariate Gaussian Distribution to Predict Range of Movement

I am currently attempting to use a bivariate normal distribution to identify the most likely range of movement for a blob in computer vision. This itself is not the problem, however; I do not ...
2
votes
2answers
325 views

Visualization of Cantor set by Mathematica or Maple!

We all know what it is the Cantor set. The Cantor set is created by repeatedly deleting the open middle thirds of a set of line segments. One starts by deleting the open middle third $(\frac{1}{3}, ...
2
votes
1answer
234 views

Closed form with of a series Mathematica

I've these two series, and I would like a closed form: $$ \sum_{k=-\infty}^{\infty} \frac{x+kx_0-h}{|x+kx_0|^3}$$ $$ 3\sum_{k=-\infty}^{\infty} \frac{(x+kx_0-h)(x+kx_0)^2}{|x+kx_0|^5} $$ ...
3
votes
0answers
135 views

Perturbation problem

This is a mathematica exercise that I have to do, where $y(x) = x - \epsilon \sin(2y)$ and it wants me to express the solution $y$ of the equation as a power series in $ \epsilon$.
0
votes
1answer
127 views

Euler's Numerical method help

Consider this differential equation, $dy/dx = x + \sin(y)$ with initial condition $y = 0.5$ when $x = 1.2$: Write down the recurrence relation for Euler's numerical method ...
0
votes
0answers
133 views

How can I show that a given system of differential equations is stiff?

I was writing a program to solve a system of equations with Runge-Kutta method, but it doesn't work well and I decided to check what Mathematica can say about it. It turns out that I have a stiff ...
1
vote
0answers
222 views

(Improved; Kindly assist )CSI Forensic Maths

In a square room with 7 m-long sides, five people have shot at random people. They all had two bullets and killed two people in the crowd. Other people in the room were not hurt. CCTV recordings show ...
1
vote
1answer
153 views

Expanding squares and simplification of equations

as i'm reading a paper "An Underdetermined Linear System for GPS" By Dan Kalman i understand the paper but when i traced the equations there's something i don't understand ,may be my mathematics is ...
0
votes
2answers
152 views

Integrating with vector coefficients in Maple

I'm trying to use Maple to do something like this integral: $\displaystyle\int \frac{a\mu-b}{||a\mu-b||^3} \mathrm{d}\mu$ Where $a, b$ are vectors and $\mu$ is a scalar I'm integrating by. But I ...
3
votes
1answer
175 views

Method For Constructing Self Referential Formulas Like Tupper's

Can anyone please explain exactly how formulas like Tupper's self referential formula can be constructed? I'll like to see the reasoning behind the derivation of such formulas and the steps required ...
0
votes
1answer
58 views

What is Mathematica option to check whether trigonometric equality is true or false?

What is the TrueQ analog that recognizes trigonometric equalities?
0
votes
1answer
98 views

How to find a parametrization of a equation and to draw its picture.

I was wondering how to find a parametrization of $(x-t)^2+(y-t^2)^2-t^2=0$, and how to use a software like Mathematica to draw a picture of this equation based on the parametrization. Thanks in ...
0
votes
2answers
814 views

How to draw a family of curves and its envelope?

Given a family of curves $$F=(x-t)^2+y^2-\frac{1}{2}t^2,$$ I am trying to compute the envelope of this family. The envelope is described by the equations $$F=0, \\ \dfrac{\partial F}{\partial t} ...
1
vote
1answer
62 views

can't figure out what I been doing wrong on simple integration question

$$\int_0^1 \sqrt{(\sqrt{5})^2+(2t)^2}\;dt$$ Based on the formula $\int \sqrt{a^2+x^2}\;dx=\frac{1}{2}[x\sqrt{a^2+x^2}+a^2\log(x+\sqrt{a^2+x^2})]$ I just plug in above input into the formula above ...
1
vote
5answers
659 views

Numerical solution in Matlab or any other solver

I need to find x of this equation: 1.0221044505936159^x + 1.0446975079232772^x + 1.0677899723724409^x + 1.091392883061106^x + 1.1155175231229544^x + 1.140175425099138^x + 1.1653783764512973^x + ...
30
votes
3answers
371 views

Do we really know the reliability of PrimeQ[n] (for $n>10^{16}$)?

The algorithm Mathematica uses for its PrimeQ function is described on MathWorld. That web page says PrimeQ uses, "the multiple ...
18
votes
1answer
6k views

Is Sage on the same level as Mathematica or Matlab for graph theory and graph visualization?

The context: I'm going to start working on a project that involves running predefined algorithms (and defining my own) for very big graphs (thousands of nodes). Visualization would also be welcome if ...
0
votes
1answer
142 views

How could calculate this definite integral by mathematica software

I have a expression given as $F=f_1(x)+f_2(x)+\cdots+f_N(x)$ Now I want to simplify this integral as FullSimplify[$\int \limits_0^\infty F \;dx$]. It takes along time to calculate. If I factor it into ...
0
votes
1answer
89 views

Solving a one line matrix, constraining the coefficients

I will give a simple example of my question then the full one. Let's say I am trying to reconcile my bank account, and have no statement. I opened it with $0 exactly, and a small number of ...
2
votes
2answers
472 views

Finding root of a polynomial

Let's say I've got $ax^3 + bx^2 + cx + d = 0$ I want to find x for a general-case. Mathematica gave me a very long solution, and even longer for one which has $kx^4$. Can you please help me ...
4
votes
3answers
1k views

Is it A Good Idea To Write Papers With Mathematica?

I find it very easy to write with mathematica. There are a lot of templates to choose from, and the formula visualization is cool. Also it's very convenient to manage chapters and sections. With ...
2
votes
1answer
224 views

Two questions on integration of $\operatorname{sech}x$, one with Mathematica

So I have a two fold question, one I believe is simple but my algebra seems to be off, the other involves the trapezoidal rule of integration using Mathematica as an aid. Here they are: $1.\quad ...
0
votes
1answer
793 views

Mean Residual Life, clarification needed

I had previously posted this question at StackOVerflow but given it seems more about probability than programming I thought this forum mind give it a more suitable environment. I need to understand ...
1
vote
1answer
172 views

p-norm of series / Mathematica

When computing the $p$-norm of the series $x_n = \mathrm e^{\mathrm i n}$ for $n \in \mathbb{Z}$ (not $\mathbb{N}$), the sum should not converge: $$\|x\|_p^p = \sum_{n \in \mathbb{Z}} (\mathrm ...
0
votes
1answer
2k views

Plot Y-Range on Mathematica

I have a plot that I would like to slightly manipulate in Mathematica. Here is the code I am entering: Plot[{x, 2^x, log_2(x)}, {x, -1, 3}] As you can see $x$, $2^x$, and $log_2(x)$ are all ...
0
votes
1answer
196 views

Automated generation of a parametric plot?

Currently we are introducing integrals of manifolds in $3d$-Space in a course. We are given some set $E \subset \mathbb{R}^3$ and should evaluate the surface and scetch how it looks. For example ...
0
votes
1answer
399 views

Q-Test in mathematica

I want to use the Q-test to determine outlier in my dataset. However, I cannot find a function to do this is in Mathematica. Does anyone know if there is a function which does this in Mathematica? ...
3
votes
0answers
312 views

How plot the Riemann zeta zero spectrum with the Fourier transform? [closed]

This question is closed as off-topic and duplicate of How plot the Riemann zeta zero spectrum with the Fourier transform in Mathematica? In the paper "The Riemann Hypothesis" by J. Brian Conrey ...
0
votes
2answers
292 views

Ackermann function

I have trouble with a question i need to use the function of Ackermann, I need to show that Ack(2,3) = 9. ...
2
votes
0answers
174 views

Mathematica: Solve function problem [closed]

I have entered the following commands in Mathematica: ...
2
votes
1answer
350 views

Finding General Expression from recursion

I am trying to find a general expression from a recursion. Here it goes: $(x+i)P_i = (i+1)P_{i+1} + \frac{x}{2} P_{i-1}$ $i$ goes from $0$ to $S$. How can I calculate a generic $P_i$ in terms of ...
1
vote
1answer
71 views

Finding the fit $A\ T^a+B\ T^{-b}\ \rightarrow\ C\ T^c\exp{(\small{-\frac d T})}$ for an interval? (specifically in Mathematica)

I'm given an expression $$A\ T^a+B\ T^{-b},$$ $$\text{with} \ \ \ \ A,B>0,\ \ \ \ a,b\in(0,1),$$ but the plus sign "$+$" is a problem for my purposes. I want to make a fit of the following ...
0
votes
1answer
61 views

Help Plotting in Mathematica

I have a function of the form S=f(x,y,z), 0 ≤ x ≤ 1,0 ≤ y ≤ 1, 0 ≤ z ≤ 1. I would like to solve S=0 numerically and plot the solution set of (x,y,z) in 3-space
1
vote
1answer
2k views

Error When Using Mathematica To Solve Differential Equation

I have a concern of why mathematica does not like/except the independent variable x. When it is used it gives the following error: In[1]:= DSolve[{2 x''[t] + ...
4
votes
0answers
155 views

Paradox running times of Reduce for polynomial inequalities in Mathematica 8 [closed]

I found something odd about the time needed by Reduce to solve a polynomial inequality (under Wolfram Mathematica 8). Consider the following: ...
1
vote
1answer
82 views

See currently assigned variables in Mathematica

I've noticed that in a notebook, if I define a variable, and then delete the definition, the variable stays assigned. Is there a quick way to see all the variables that are assigned? I can find them ...
1
vote
3answers
408 views

How to plot $z= 5-\sqrt{x^2+y^2}, 0 \le z \le 5$ in mathematica?

Could anybody tell me how to plot $z= 5-\sqrt{x^2+y^2}, 0 \le z \le 5$ in mathematica? I haven't done much on multivariable yet, but I am inquisitive to know how to plot this cone on mathematica? ...
2
votes
3answers
217 views

What is the analytic form of MeijerG in Mathematica?

I know that the official standard formula can be found here, but I am having a very hard time simplifying this special case: ...
-3
votes
1answer
236 views

How to solve this integral of trigonometric f in Mathematica

How to solve this integral in Mathematica Is it possible to solve it numerically? $$\begin{align} \int_{-1}^1 \cos\big(&(.75-.75x^2)\cdot y_1 + (.25 - .5x - .75x^2) \cdot y_2 \\ + &(-.5x ...
1
vote
2answers
5k views

How can I calculate the centroid of polygon?

What is the way to calculate the centroid of polygon? I have a concave polygon of 16 points, and I want know the centroid of that. thanks