0
votes
1answer
11 views

Fighting the Current

I am working a problem I am working on. A boat start across a river at the point (c,0) and points its bow directly across the river to the point (0,0). The parameter a is the river current velocity, b ...
0
votes
0answers
5 views

PDE of real-world system, integral boundary condition

I've stripped all the physical-significance for clarity, but I know that u[x,t] will be everywhere positive and continuous. here are the equations in Mathematica code: ...
0
votes
0answers
6 views

Problems with a constant term in an Integrate command

When asking Mathematica to integrate a function with Integrate, I'm getting drastically different results depending on whether I have a proportionality constant ...
0
votes
0answers
4 views

How to combine two or more groups while selecting form the unbalanced panel data if the number of obs is less than a scalar in certain groups

I have an unbalanced panel data. I want to calculate group statistics for each group. However, if ith group has less than K obs, then I want to combine ith and (i+1)th groups to calculate group ...
0
votes
1answer
13 views

Clicking on “Show all results” in a W|A pod hangs Mathematica

I am trying the brand new trial version. I type in =Forest Gump, then the Enter key. The input turns into a box with a plus sign in the upper right corner. When I ...
1
vote
1answer
29 views

How to import a file for processing but not for displaying?

Here's my problem, I want to take what I have now for code ...
0
votes
1answer
20 views

Speeding up a differential equation system with Events

I have the following differential equation system with periodic Events : ...
0
votes
1answer
34 views

Exporting a Mathematica Document as LaTeX [on hold]

I have tried several times to import a Mathematica document into a Wiki using the "Export As Latex" option. It never works. Of course I have the option of copying each stretch of text as text and ...
0
votes
0answers
17 views

Boundary value problem with FDM in Poisson PDE [on hold]

Thanks for the answers for my previously question. I find a solution for Poisson PDE in polar coordinates but now I have a problem for boundary ...
0
votes
1answer
58 views

Solve reports it can't handle my equation

I am trying to solve the following equation Solve[x ϵ + (-ϵ) x^-ϵ - c (-ϵ) x^(-ϵ - 1) == 0, x] Yields Solve::nsmet: This system cannot be solved with the ...
0
votes
0answers
20 views

How to handle solution returned by ParametricNDSolveValue in FindRoot

i was trying to solve a problem relative to root finding in a system of differential equations; here's a simpler case. With two distinct set of parametric differential equations, i'm able to find the ...
10
votes
6answers
173 views

How to sort digits in a string while keeping other characters untouched?

Now there is a string with digits and letters, for instance, "95uge678r3gi89hgfe30kgh063d51". And the expected output is ...
0
votes
2answers
40 views

Vector optimization with vector length as a free variable

I'm trying to solve the following problem: For a vector $v$ of length $c$, $\min \frac{\sum v[i]^4}{(\sum v[i]^2)^2}$ subject to $\sum v[i] = N$. I can solve this numerically for a given $c$ using ...
1
vote
1answer
42 views

Integer partitions and dice result probabilities

This is a Project Euler question, so no spoilers :] I was going to try to solve it by first finding how many ways a certain sum can be acquired from a number of dice using ...
1
vote
1answer
46 views

Using a progress bar in a functional expression

If we have a procedural construct like a Do loop or Table, it is straightforward to make a progress bar to indicate the percent ...
-1
votes
0answers
42 views

How can I verify double integral solution?

I have a double integral as follows \begin{equation} 1-(\int_0^\infty (\frac{Cje\cdot Cte \cdot e^{\frac{-w}{Cte}}}{(Cte+Cje \cdot w)^2} + \frac{e^{\frac{-w}{Cte}}}{(Cte+Cje \cdot w)}) ...
0
votes
0answers
57 views

What are the possible topics for graduate dissertation using Mathematica? [on hold]

I am a graduate student. I am planning to do one year project work on linear algebra using Mathematica. Until now i have studied transformations,elementary canonical forms ,rational and jordan ...
-1
votes
1answer
50 views

How can I plot a graph of an integral?

I want to plot the following function: $$\int \left(\frac{\Gamma (x+1)}{2}-\frac{\Gamma (x-1)}{2}\right) \, dx$$
-1
votes
0answers
33 views

Solve inequlities for certain variables. Reduce is not helping [on hold]

Working with few inequalities where two unknowns are there I wanted to find the relation between them. Reduce is unable to give me an answer. What could be done ...
1
vote
1answer
44 views

DSolve for a huge linear inhomogeneous ODE in parallel

I have a linear inhomogeneous ODE with constant coefficients, which I need to solve symbolically. The problem is that the inhomogeneity is sum of more than 100 terms (however, each term itself is ...
1
vote
0answers
64 views

Is it possible to write popular journal in Mathematica? [on hold]

As you know, Latex is the most popular toolbox in writing the popular journal articles, like PRL or APL. However based on the "style notebook" in Mathematica shows that the layout of Mathematica is ...
-3
votes
0answers
27 views

Get function creating variables inside [on hold]

I want to use Mathematica to create this function in pseudocode: ...
3
votes
1answer
37 views

Get .NET Link to work on Raspberry Pi

Is it possible to get the .NET Link working on Raspberry Pi? I understand that Linux and MacOS versions of Mathematica come with .NET Link running on Mono and now even possibly under new open-source ...
-1
votes
0answers
42 views

What does F[[1]] mean? [on hold]

I defined a function "F" and checked length, then I wanted to select terms I needed, and failed. One of my friends said I should typed something like that: ...
0
votes
0answers
29 views

Topics for master's project using Mathematica [on hold]

I wish to do 1 year project in linear algebra using Mathematica. What are linear algebra topics which can be implemented on Mathematica as part of 1 year graduate level dissertation.
1
vote
1answer
61 views

4th-order Runge-Kutta method to solve a system of coupled ODEs [duplicate]

I am a beginner at Mathematica programming and with the Runge-Kutta method as well. I'm trying to solve a system of coupled ODEs using a 4th-order Runge-Kutta method for my project work. I have ...
2
votes
1answer
78 views

Proving positive definiteness or semi-definiteness of a matrix

I have the following 4x4 real symmetric matrix: $K=\begin{bmatrix}3-3w & -\frac{4}{3}+a+2w & \frac{5}{12}+b-\frac{w}{2} & 0\\ -\frac{4}{3}+a+2w & -1-6a-3x & ...
0
votes
0answers
27 views

How to use RunProcess to run python interpreter

In a related question How to use RunProcess to import external function? @taliesin provides a very nice answer illustrating using RunProcess to launch a GO http server. Has anyone, or does anyone ...
2
votes
4answers
134 views

Using Map sequentially

I'm trying to simulate the probability of a balanced hand in Bridge (The Theory of Probability by Santosh S. Venkatesh, 2013) using Mathematica. The problem is solved in the textbook but I just wanted ...
1
vote
2answers
50 views

How to make legends in Graphics?

To make an equilateral hexagon, here is my code in mathematica: ...
1
vote
1answer
48 views

Writing cells from other notebooks into current notebook?

I have a large number of Mathematica notebooks which contain study notes for different topics (as opposed to actual Mathematica Code). I'm trying to develop some code to randomly pull parts of a ...
1
vote
2answers
49 views

NotebookWrite in EvaluationBox forces Input CellStyle

There is a promissing new function EvaluationBox[] and a nice last example in documentation section for it: ...
1
vote
0answers
23 views

How would I set the equation number for an EquationNumbered cell?

Regardless of how many EquationNumbered cells are above or below, every new EquationNumbered cell that I add in my notebook shows (1) as the equation number. Is there a way to correct the equation ...
1
vote
1answer
73 views

How can I simplify a triple integral with exponentials?

I want to simplify the following triple integral with exponential terms. \begin{equation} \int_0^\infty\int_0^\infty \int_0^\infty \frac{1}{R\,G} e^{-p(1+R\,a)-q\, b \frac{1+R\, a}{1+G\, x}}\, ...
1
vote
1answer
55 views

speeding up creation of SparseArray

I have to create the following sparse arrays, which are reshaped in a two dimensional matrix, so that i can use the build in Dot[] function to do a kind of ...
10
votes
5answers
367 views

Opposite of StringSplit

What is an appropriate command that does the opposite of the following. StringSplit["a b c d e f g"," "]
1
vote
0answers
140 views

Mathematica 10.1 availability [on hold]

According to this post and this page of the Wolfram Documentation Center a new Mathematica version is on the way, if not already available to some user. It'll be v. 10.1 and, as such, a rather major ...
1
vote
0answers
29 views

DateObject from AbsoluteTime broken

In the middle of a session (10.0.2 / Win64 / 2.7Gb working set - peak was over 7Gb) the form/definition for DateObject from an integer has disappeared. ...
4
votes
1answer
181 views

Lagrange Multiplier

We are asked to maximize and minimize $f(x,y)=4xy$, given the constraint $4x^2+y^2=8$, using the Lagrange Multiplier method. First, I enter the functions f and g. ...
2
votes
1answer
60 views

How can I get “custom” controls to appear and behave like “default” controls in my Manipulate?

For various reasons I need to define some controls in my Manipulate with complex behaviors that are not (or at least I don't think can be) accomplished using the ...
0
votes
0answers
26 views

Boundary Value Problem Errror [on hold]

I have a first order differential equation such as $\quad \quad d/dt (u[x,t]) = - u[x,t]\,u[x,t]$ with the boundary conditions $\quad \quad u[0, t] = 0,\ u[L, t] = 0$ where $x$ is between $0$ and ...
1
vote
0answers
14 views

Speeding Up the Numerical Integration of a Product of Numerical Integrands with NIntegrate

I need to solve a set of coupled integral equations within a self-consistent cycle. The final result will be functions, say $A(x)$ and $B(x)$, which are related to each other by some integrals which ...
0
votes
0answers
39 views

How to enlarge the plot without the legend (or label)? [duplicate]

I have 3 plot with legend on top. However when I array them in one row, plot is small. Then I tried to enlarge the output graphics, every graphic cannot enlarge except the gap. How to solve this? This ...
1
vote
1answer
106 views

Integrated Solution Graphics [on hold]

I want to draw this nonlinear differantial equation' graphic with other solving equation (in same graphic). ...
4
votes
0answers
28 views

Solving a PDE with a spatially piecewise-constant material parameter

I would like to solve equation for the 2D distribution of an electrical potential in the conductive medium: div(sigma*grad(f))==0 where f=f(x,y) is the electric ...
0
votes
0answers
52 views

Is there a way to create a two column page layout in a notebook? [duplicate]

I am working on a white-paper that requires a two column format. Is there an existing Stylesheet that can be used or a way to create a Stylesheet that supports this Mathematica?
4
votes
2answers
107 views

Well-defined symbolic integral leading to ConditionalExpression

I would like to determine a closed-form expression for the following symbolic integral $$ \int_{-1/2}^{1/2} \!\!\!\! \mathrm{d} x \int_{-1/2}^{1/2} \!\!\!\! \mathrm{d} y \, \frac{1 + b x + c y}{1 + e ...
1
vote
1answer
72 views

How do I smooth or remove jitter from an exported Graphics3D plot?

I have exported a Graphics3D plot as gif. But the plot shows jitter (You can see the yellow ball shows somewhat slight move around, which is expected to be still). How does this happen and how to get ...
0
votes
1answer
56 views

DensityPlot and KroneckerDelta

I have the following DensityPlot: DensityPlot[Sin[x] Sin[y], {x, -Pi/4, Pi/4}, {y, -Pi/4, Pi/4}, ColorFunction -> "SunsetColors", PlotLegends -> Automatic] ...
4
votes
1answer
64 views

Comparing memory consumption of two pieces of code

I have implemented something I want to do in two different ways, because I'm not sure which of the two approaches give best speed/memory efficiency. Comparing the speed of the two approaches is ...

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