# All Questions

34 views

### Problem with NMinimize

First of all, I want to clarify that I'm quite new to Mathematica. I searched a lot on this site to learn how to solve my problem, which this is the problem of my life! I want to minimize a function. ...
58 views

### Plotting the solution of a Chini differential equation

In DIFFERENTIAL EQUATION SOLVING WITH DSOLVE by D. Kapadia, there is a Chini differential equation : sol = DSolve[x'[t] == 5 x[t]^4 + 3 x[t]^(-4/3), x[t], t] ...
5 views

### Changing font size and style in VectorDensityPlot

I have this: VectorDensityPlot[{x, -y}, {x, -5, 5}, {y, -5, 5}, PlotLegends -> Automatic] and want to: 1) Add a label to the column bar legend on the side ...
8 views

### How can I move he documentation to another location after install on Windows?

How can I move he documentation to another location after install on Windows? I would like to move the documentation to another partition on my Windows filesystem. Michael Hale in chat recommended ...
19 views

### NSolve and domain specifications

I am using NSolve to find roots to a system of polynomials that describe some chemical reactions. However, I am seeing some odd behavior when I restrict the domain. First, the basic setup: ...
41 views

### Simplifying integer inequalities to equality

I try (in Mathematica 10) FullSimplify[l >= l1 + l2, {l <= l1 + l2, Element[l | l1 | l2, Integers]}] But that gives back ...
19 views

### Working with WolframCloud

I'm using WolframCloud from my smartphone and I'm having trouble to select all the cells of my notebook to delete them. There is a command that selects all the cells in a notebook? I tried using the ...
30 views

### Pointers in Mathematica

Does Mathematica entertain Pointers in wolfram? I have a matrix and I want to make function At such that At(MatrixName,row,col) = NewValue I am able to update the ...
27 views

### Fourier Transform for Blazed Fork Grating

I built blazed fork grating on Mathematica and the idea of using blazed fork grating instead of normal one is to eliminate the other diffracted order. So the blazed fork grating will let only the 1st ...
12 views

### Memory leakage with NDSolve

This is not the first time the question in mentionned (cf in particular this recent question NDsolve memory leak), but there seems to be a serious issue of memory leakage - or am I missing something? ...
11 views

### Is there a Wikidata - based Entity system yet?

Wikidata.org seems to have a similar goal as the new Entity/EntityProperty Wolfram-knowledge base system. The differences are that Wikidata is open, promising faster expansion and fixing, but of ...
31 views

### How to confirm that computation uses multiple CPUs?

I have a multi-cpu machine, as shown below: ...
182 views
+100

### Symbolically prove that two expressions are identical

I encountered this problem when trying to reproduce the result of this paper. I want to prove int == intpaper assuming ...
339 views

### Distributing function arguments with function compositions. How to compute $(f + g^2)(x) = f(x) + g(x)^2$?

Suppose I have two functions f and g. To compute $f + g$ evaluated at a point $x$, I know that one can use ...
43 views

### Web Browsing Automation: how to expand all comments under a blog post?

I wish to expand all the comments under a LiveJournal post for the purposes of saving the complete thread of comments. According to LiveJournal's FAQ when a post gets more than 50 comments they are ...
24 views

### Why isn't LowPassFilter working for these parameters?

First I define a function, just a sum of a few sin waves at different angular frequencies: ...
13 views

### ContourPlot with custom ColorFunction: Odd behavior of “Contours” option?

I am trying to generate a blue-cyan-green-yellow-red color gradient that is linear in Hue. The code ...
10 views

### Import[] .obj data with per-vertex colors?

There's a somewhat standard way of including per-vetex color with obj files: Geometric Vertex A vertex can be specified in a line starting with the letter "v". That is followed by (x,y,z[,...
72 views

### How to generate a Markov Matrix efficiently

A Markov Matrix is a square matrix,which have two features: All elements great than or equal to $0$(But I hope all element great than or equal to $0.1$) All the columns add up to $1$ I have a ...
30 views

### Remove columns basing on binary sequence

Possibly it is duplicate, still I could not find here elegant way to remove matrix columns basing on binary sequence. i.e. if I apply {1,1,0,0,1,0,1} to matrix it should delete columns 3,4 and 6.
29 views

### How to speed up NIntegrate when using an interpolating function output from NDEigensystem?

I have been working with NDEigensystem in order to find the resonant frequencies of different shaped drums. I would also like the coefficients of the different eigenfunctions so that each of these ...
171 views

### My code uses ClebschGordan but Mathematica is using ThreeJSymbol

I'm using a function that calculate CG coefficients with the function ClebschGordan but instead, I've got the following error because Mathematica is using ...
96 views

### Solve 3D Electric Field using FEA

The objective is to solve the 3D electric fields for the geometry below and generate the continuous function eField3D[x_,y_,z_]. The method I was planning on using ...
422 views

### how to get $n$ equidistributed points on the unit sphere

We can get $n$ equidistributed points in the unit circle using CirclePoints. But how do you get $n$ equidistributed points on the unit sphere(surface of a ball)? ...
26 views

### Running complex functions in parallel

I've got a module containing a loop and multiple calls to other functions, i.e. ...
423 views

### How to implement custom integration rules for use by NIntegrate?

How can NIntegrate be extended with custom implementation of integration rules? This answer of the question "Monte Carlo integration with random numbers generated ...
61 views

### Boolean function from incomplete truth table

BooleanFunction in mathematica can convert an input truth table to a Boolean function. It can do so even if the truth table is incomplete. But the interpretation of truth table obtained from such an ...
84 views

### Union sorting after ignoring some digits

I have a list with its bellow elements: {-0.7071067811865476, -0.7071067811865475, 0.7071067811865475, 0.7071067811865476} If I use ...
139 views
+50

### Finite difference method not converging to correct steady state or conserving area?

I am working with the following PDE, which is an advection-diffusion type equation. It describes the movement of a fluid-fluid interface inside an annulus of inner radius $R_1$ and outer $R_2$ under ...
45 views

### Helping Solve to solve

I am developing quite an involved bit of code (for me) that is not finding solutions with Solve when it should. The relevant part of the code is ...
95 views

### Is the MMA formulation correct?

Let $H$ be a $4\times 8$ matrix and $R$ is a vector of 2 elements. ...
1k views

### I failed to solve a set of one-dimension fluid mechanics PDEs with NDSolve

The fluid here has been assumed as single component perfect gas i.e. it obeys the equation $p=ρ R T$, the thermal conductivity is assumed as a constant, so the equation set is: ...
121 views

### Multiple scripts run using same kernel

I have an external program that calls Mathematica scripts upon certain events. Each script requires a large Mathematica library to load (takes a while). Is there some way to run an initial script ...
2k views

### Web Browsing Automation with Mathematica

I want to build a bot to automate web browsing, this mean something like: filling forms press "submit" buttons find certain text inside pages and so on... How can I do this with Mathematica? The <...
23 views

### Priority on Fitparameters

I try to fit a function using the FindFit expression. My problem is that ZL has to be ...
100 views

### How to 3D-plot with specific ranges?

I have the following function which I want to plot using Plot3D: (-1 + w + 3 s w)/(2 (-1 + w + 4 s w)) , which is only ...
61 views

### How do I save the generated 2d random array for the next using?

I generated a 2d random array in $x-y$ plane with L = 10; random = Table[{x, y, RandomReal[{-1, 1}]}, {x, 0, L, L/10}, {y, 0, L, L/10}]; Now I want to save it ...
41 views

### Surface fitting involving factorial function

I have a large data set made up of triples, (x, y, f(x,y)), x, y and f(x,y) are all integers. I don't know the function f(x, y) and my goal is to find (estimate) it. I do know that x can be any ...
72 views

I am solving a system of non linear differential equations. The time needed to solve them is quite long and I would like to shorten it. Is it possible to send the NDSolve command to be solved by the ...
226 views
+50

### The unexpected behavior of FindMinimumCostFlow?

I need to verifiy which behavior is a bug or I misunderstand the documentation.So I give a bounty for it. I'm at a loss to understand the behavior of the ...
149 views

### Identifying and removing features from scanned handwriten text

Please, can I have some ideas and help on how to identify and remove features like this one or this one from scanned handwritten text like this: These features are not connected to other text ...
9k views

### How do I identify the source of a “Tag times protected” error?

I have some code that looks like Table[ a = 1; b = {2, 3} c = i;, {i, 2} ] which gives an error: Set::write: Tag Times in c {2,3} is ...
38 views

### Replicating same output in Mathematica from Matlab [on hold]

I have a code in matlab: ...
40 views

### Partial Differentiation with interpolation function

I'm trying to take the partial differential of each component of an interpolation summed together. It works fine when I do it with an algebraic expression, but I can't understand why it doesn't work ...
143 views

### Export and manipulate 3D plots

How can I export 3D Mathematica plots such that I can put them into a presentation and still being able to rotate them? Is there a specific format or does it depend on the program used to create the ...
3k views

### How to place CDF file in Microsoft Word, Powerpoint or in interactive PDF file?

I would like to create a presentation for my lecture in which I would use Mathematica CDF files. Let's say I want to have such interactive content: ...
605 views

### How to convert Graphics3D object into an Image3D object?

How does one convert a Graphics3D object into an Image3D object? E.g., start with ...
146 views

### Where does a package have to be loaded?

I'm trying to solve a very tricky bug in my program. It's tricky because it seems to be not working intermittently, and mostly not working when running with large data sets. The code itself is kind of ...
93 views

### Refresh plot during heavy calculations

I have some heavy calculations with generates huge list of {x,y} points. I want to dynamically update plot during calculations. Or update it after calculations complete. I cant use simple Dynamic@Plot,...
I am working on problems related to the pdf q[y] where $y=Log[f]$ and f[x] is a known pdf in x. But I can't figure out how to ...