# All Questions

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### Need help to solve this math question when x reach 0 [on hold]

My son can home and ask me to help him with this equation: lim ((x-2)/(2x-1))^(1/x) x→0 I try to use /www.symbolab.com but its too complicated to solve this. Thanks with the help
356 views

### A better simplification function

I am creating this question and posting an answer to it as a help for those who have problems with Mathematica simplification oddities that appear in many other questions on the site. First of all, ...
45 views

### Series of integrate in exponential

Why Mathematica cannot perform this series: ...
32 views

I guess this has already be answered. Plot[1/(x^3 - 2 x^2), {x, -2, 4}, Exclusions -> True] Plot[1/(x^3 - 2 x^2), {x, -2, 4}, Exclusions -> 2] I cannot ...
113 views

### Evaluation problems with NDSolve using the fixed step ExplicitEuler-Method

Motivation I am using Mathematica to implement System Dynamics (SD) models, e.g. differential equation models as applied to management/economic problems following the "methodology" of Jay W. ...
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### Can LinearSolve use Parallelize and WorkingPrecision in computation

I am looking for a two things while calculating the large array matrix equation: 1) To increase the precision in simple LinearSolve[] function 2) To find a way to parallelize the computation on all ...
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### Solving ODE having function which changes conditionally

I want to solve the following set of ODE with a piecewise function A[t] which changes if a certain condition is satisfied. ...
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### Solving a delay partial differential equation

I am trying to solve the following partial differential equation, $$\frac{\partial\phi[t,x]}{\partial t}=-2\pi\ \delta \ e^{-t}\phi[t,\mu]^{-2} \frac{\partial}{\partial x} \phi[t,x](x-\mu)$$ where ...
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### Shorter code for repetitive commands [duplicate]

How to give a shorter one or two line command without repetition (single variable change in a subroutine): ...
25 views

### Changing font of plot axes labels [duplicate]

I was wondering if anyone knew how to make these 2 plots in Mathematica (or any software in which we could). I have the font (it's the LaTeX font) but I am not sure how to set the axes' font to that. ...
55 views

### Discrete Measure between Binary Vectors

I would like a discrete distance measure between two binary vectors (or strings). Like HammingDistance but I want the vectors to be considered closer if they have ...
41 views

### Adding circles on a function plot depending on the slope

I have the following function and I use manipulate to change the plot of the function and the integral respectively. In nonlinear dynamics one plots a little circle/point on the intersections of the ...
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### Disassambling a boundary mesh into pieces and building it back again fails. Why?

I have just a misunderstanding of a sort. What I want is (1) to build a boundary mesh, (2) then to disassemble it into a list of the boundary points, and (3) to further assemble it back starting from ...
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### Beginner: Iterative Sequence for Vector Function

I want to create an iterative sequence for two Vectorfunctions, where both are dependent on the same variables and i represents the vector. For simplicity let's ...
157 views

### Possible Method for MatrixExp

Well, probably a hard question, but I think it's better to cry out loud :). I noticed that MatrixExp owns Method option when ...
34 views

### Mathematca terminates internet connection when window is minimized

I wrote a short program which is collecting (and then plotting) data from internet. When I literally don't see, Mathematica stops collecting data and when I maximize window again, it continues. Can ...
18 views

### Need help with a hyperbola/parabola equation solving for an assignment [migrated]

Hi so i was given my Math C assignment today and the moment i looked at question 1 i knew i had no idea what to do. This is the graph i was given (http://imgur.com/nRXOlJy). I was asked to provide an ...
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### Give the result in separate lines

I have the following command Reap[Do[If[GCD[i, 7280] == 1 && Mod[729*i, 7280] > i, Sow[{i, Mod[729*i, 7280]}]], {i, 0, 7280}]] which gives pairs ...
260 views

### What are SparseArray Properties? How and when should they be used?

A strange undocumented form of SparseArray is increasingly used in answers on this site: ...
51 views

### Apply every function from a list to an expression

I would like to apply a list of functions to an expression, like ApplyList[{Re, Im}, Exp[I x]] = {Cos[x], Sin[x]} How do I do that?
27 views

### How to refine the approximate solution of an implicit function? [on hold]

I have an equation of the form exp(A(C-x))-1-exp(x-B(C-x)^(2/3))=0 Here A,B and C are constants, x is the unknown, I want to find, but approximate value of x is known. so, the problem is how to get ...
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### Discrepancy in the series expansion of $\log(z/(z-1))$ in Mathematica 5

When I calculate the series expansion of $\log\frac{z}{z-1}$ around $0$ in Mathematica 5.2, I obtain: ...
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### Is it possible to solve a certain set of nonlinear equations in Mathematica?

I read this question in a Chinese forum last year. At the end of the discussion, they provide a solution of the equations from a C++ program. Unfortunately, they did not get the right answer. ...
59 views

### ParametricNDSolve without initial condition?

For example, ParametricNDSolve[{y'[t] == a y[t]}, y, t, {a}] returns a ParametricFunction which is actually inexplicable: ...
204 views

### How to make Mathematica show matrices and vectors nicely

It shows me like {{0}, {1}, {0}, {-1}} . Is it possible to make it look like a vector, always?
44 views

### Animating a Sphere to move along a 3D curve [on hold]

How do I get a sphere to move along a 3D function in Mathematica?
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### Add text or descriptions to Plot

I would like to add some descriptions or qualifications to Plot as follows: Those in black are what I would like to add to my Plot (this graph is manually created ...
71 views

### Choosing FEM element type and mesh refinement

I have only recently been introduced to Mathematica's(v10.0) FEM capabilities. I understand that for solving PDEs on non-uniform shapes via NDSolve, Mathematica ...
36 views

### How to print unevaluated arguments in the form they were originally typed in?

I'm looking for a way to print a function's arguments, not only unevaluated, but also in the way they were originally typed in. By way of experimentation, I tried stuff like this: ...
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### AVL binary search tree implementation

Is there any text-book implementation of self-balancing binary search trees such as AVL or red-black in Mathematica?
47 views

### How can I have this $\LaTeX$ expression in my Mathematica code? [on hold]

I'm trying to make this happen in Mathematica: $\mathscr{G}_{\text{\textbullet}}$ $\mathscr{G}_{\text{\textbullet}}$ I tried ...
71 views

### Intersection of a ListPlot3D surface with a plane

I'm trying to use Mathematica to analyze some physics data from an experiment, more precisely, I have to fit a 2D data series with a one dimension function. At the moment I'm able to load and plot ...
28 views

### How to get Mathematica to abort the current evaluation if an assertion fails?

I can turn on assertions, but they don't terminate the current evaluation. For example: ...
49 views

### How can I perfect this game for Wolfram Demonstration publication? [on hold]

When the messages change the window inactivates, and when I try to host an interactive CDF on my site it turns red and says something about numbers having to be scaled or offset. Any help? I'm ...
30 views

### Error message with Animate?

I have a error message, but after I execute ndsolve cell is all right.What is the Reason for this error? ...
27 views

### Using Quantity[] units causes errors in my calculation

I have an interpolation function in which I wish to use actual units. If I perform the calculation normally, it works fine and returns a proper FittedModel. To illustrate my problem, consider the ...
37 views

### Generate all 3-permutations of the set {x, y, z, w, u, t} excluding the ones where 'u' is after 't' [on hold]

I have to generate all 3-permutations of a the set $(x, y, z, w, u, t)$ without the ones where the element $u$ is after element $t$. So far I have generated all the the 3-permutations like such ...
31 views

### how to read a list from a file which has mixed types of data?

I need to read in a file with the first several lines reading as ...
59 views

### Loop in a loop, or how to evaluate complex expressions

I need to find $h_{0j}$ for every $1\leq j\leq300$, where \begin{multline*} h_{0j} = \sum_{q=1}^{Q}g_qe^{-\lambda_q j\Delta}\frac{e^{\lambda_q\Delta}-1}{\lambda_q} + \sum_{p=1}^{P}\frac{e^{-\alpha_p ...
156 views

### How can I evaluate surface integral in Mathematica?

$$\iint_{S^+}x^3dydz$$where $S$ bottom part of $$\frac{x^2}{a^2}+\frac{y^2}{b^2}+\frac{z^2}{c^2}=1$$ $S^+$ - outer side of $S$ \iint_{S^+}P(x,y,z)dydz = \iint_{S}P\cos\alpha dS,\ \; normal : ...
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### How can I mark a point on a slider control?

I have a Slider control inside a Manipulate which spans some range of values, say from 0 to 10, like in: Manipulate[ Sin@x, {x, -2 Pi, 2 Pi} ] I would like ...
27 views

### Simultaneous projections ViewPoint

I have static projections and have to switch between them to change the view. Is it possible to display projections obtained with ViewPoint on the corresponding ...
46 views

### Dynamical Updating of function [on hold]

I am making a program in Mathematica that Dynamically updates the value of a variable. Tests conditional statements on the variable or calculate Mod or coefficient. Here is the code. ...
137 views

### Adding noise to nonlinear ODE system

I have a problem with adding a noise to 3d order ODE nonlinear system. I solved the system numericaly and got the periodic solution and now I need to add random pertubations. Due to the lack of ...
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### Differential equations: Solving a PDE

I need to find an analytic solution to this PDE and for some reason nothing works. This is the equation: ...
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### Create predictors and response pairs

I am new to Mathematica currently using version 10.1.0. After importing a .csv dataset of 352 rows, I select two variables (say, x1, x2, which are actually positive integers) as predictors and one ...