3
votes
2answers
231 views

Overloading conjugate operator for a particular function

I trying to modify the behaviour of the built-in Conjugate[] operator on a particular function I have defined, to take into account that some of its variables are ...
5
votes
2answers
639 views

Find all the integer numbers $a$, $b$, $c$, $d$, $e$, $f$, $k$ to this equation have three integer different solutions?

How to find all integer numbers $a$, $b$, $c$, $d$, $e$, $f$, $k$ that belong to interval $[-10,10]$, so that the equation $$\sqrt[3]{a x + b} +\sqrt[3]{c x + d} + \sqrt[3]{e x + f} =k$$ has three ...
11
votes
2answers
2k views

Solving an ODE in power series

How do I find a series solution to an ODE? I do not mean taking the Taylor series of an exact solution; I want to solve nasty nonlinear differential equations locally via plug and chug. Surely, that ...
3
votes
1answer
235 views

How to configure two Mathematica in different places with different settings

For some reasons, I should use two language versions Mathematica. The most reason is I want to see the comparison of Help page(English version and Chinese version) to improve my English, both are ...
9
votes
1answer
265 views

Efficient way to solve equal sums $x_1^k+x_2^k+\dots+x_5^k=y_1^k+y_2^k+\dots+y_5^k$ with Mathematica?

I need to solve the system of equations, call it $S_1$, in the integers $$x_1x_2x_3x_4x_5 = y_1y_2y_3y_4y_5$$ $$x_1^k+x_2^k+\dots+x_5^k=y_1^k+y_2^k+\dots+y_5^k,\;\; k= 2,4,6$$ I used a very ...
4
votes
3answers
179 views

Modify this code using Module and While

I have written a recursive function and would like to re-write the code using Module AND While to compare the timings. Here is my recursive function for f[n], where 6 n f[n] = f[n-1] + n! for n>0 and ...
5
votes
4answers
217 views

Tricky selection of elements based on their position

I need to make a list of some elements from a 4D array with dimensions 4x4x4x4. I need to select the elements based on their position in the following way: name an element e(x,y,z,w); I need all the ...
6
votes
1answer
538 views

How can I draw a polygon from a set of angles?

In recreational mathematics, polytans are polygons formed by edge-connecting isosceles right triangles. Order-n polytans are those constructed from n such triangles. My question is this: Given a ...
-1
votes
2answers
192 views

Discrete 3D Plot with date on one axis

1) How do I plot the following data in 3D (large data, only a part of it is used here): ...
0
votes
1answer
120 views

How to tell Mathematica to make assumptions? [duplicate]

Say I want to integrate 1/(x^2+a^2) and I want Mathematica to know that $a>0$. What would be the command? Something like: ...
1
vote
0answers
88 views

Distribution above pointplot [duplicate]

This is my first question here, so I'm sorry if I do something wrong. Also I'm fairly new to Mathematica (using 8). I've used it about 2 months. Only 2 weeks intensive. The rest was about ...
2
votes
2answers
117 views

Can you form a list with elements which are terms from an equation?

Is there a command that takes an equation as an input and creates an output with a list of terms in the original equation? Something like: ...
0
votes
1answer
193 views

Strange 3D plot behavior

Two Part Question Part 1: As you can see from the data and plot below, the plot does not accurately display the data sets but adds lines beyond and in different dimensions. Both u and v datasets are ...
6
votes
2answers
206 views

Variable scoping problem when mapping over delayed replacement

This is something that got me curious while I was playing around with Mathematica. Consider the following (contrived) example: ...
6
votes
2answers
351 views

How to show wireframes on imported Object / Mesh (.obj file)

I've managed to import a Wavefront (.obj) file and store it in a variable like so: ...
2
votes
2answers
627 views

How can I import images from a Microsoft SQLServer database?

I have a table with binary data (images) in Microsoft SQlServer. I want to import that data and convert it into Image format. I wrote the following code, but it's ...
1
vote
0answers
40 views

How to estimate system recource usage of a SparseArray? [duplicate]

Build a 100.000.000 by 10 element SparsArray. Fill position 1/1 and 100.000.000/10 with a value 999.999.999.999.999. ...
1
vote
3answers
262 views

List of Tribonacci Polynomials with Mathematica? [duplicate]

I want to list top ten of Tribonacci polynomials. I have following algorithm, but it doesnt work. ...
2
votes
1answer
180 views

How to combine SparseArray and If

Because I am dealing with huge matrixes, my computer can not handle it, because of the memory. But, in my matrix, a very small percentage of the elements are non-zero. So I should use SparseArray as ...
6
votes
2answers
246 views

What is the underlying algorithm for GroupElementToWord?

What algorithm is Mathematica 9 using for GroupElementToWord[group, g]?
1
vote
2answers
453 views

Translating a “Point-to-Triangle” distance script from MATLAB to Mathematica

Update - Thanks everyone for your responses! After fixing a problem with vector normalization, the code below now works. I'm a new user, and I was attempting to port some Mathematica code from ...
6
votes
0answers
174 views

Is it possible to run Mathematica on an HPC cluster with Torque?

I'm installing Wolfram gridMathematica in HPC cluster with TORQUE Resource Manager. There is a big problem because Mathematica suppost PBS pro. Can you help me or give some advice or coments?
0
votes
1answer
144 views

Dynamic Updating CreateDialog Problem

In this code, one cannot close the dialog window: {TogglerBar[Dynamic[x], Range[5]], Dynamic[x], Dynamic[CreateDialog[x]]} If I use ...
11
votes
2answers
212 views

How to generate characters by a function which works like the Esc + a + ESC

How to generate characters by a function which works like the Esc + a + ESC ...
4
votes
2answers
171 views

Graphics3D: the box vertices do not coincide with triangle

I have drawn a triangle using Line graphics primitive and Graphics3D function: ...
2
votes
2answers
341 views

Write a function that returns the logarithmic derivative

How can we write a function that if we input an expression f, it returns the log derivative $\frac{1}{f} \frac{df}{dx}$. We have to use a conditional or pattern test so that the function accepts any ...
0
votes
0answers
34 views

How to tell Mathematica to use Real Only Mode [duplicate]

How do I tell Mathematica to use real only mode. For example if I want to graph $(x-1)^{1/3}$ for $-3<x<3$, I need to use Real Only mode to get the right graph.
5
votes
1answer
160 views

Is it possible to save an interrupted computation?

I've got this really time consuming factoring problem. To decouple things a bit, I decided to start Mathematica using the command line interface (under screen). ...
2
votes
3answers
314 views

Problem with simplifying Sinc function

$Assumptions = x ∈ Reals && y ∈ Reals && a ∈ Reals && b ∈ Reals; These work: ...
5
votes
1answer
137 views

How can I substitute something using only map?

For example, I have the equation x^2 + y^2 == x*y and I want to apply the rule y -> s*x I can do it easily by ...
0
votes
0answers
39 views

Generating partitions of a set with a specified size of the parts [duplicate]

I tried the following (inspired by the answer here) myList = {a, b, c}; Needs["Combinatorica`"]; SetPartitions[myList] and I got this answer, ...
5
votes
1answer
187 views

Preventing cell height adjustment when rotating 3D graphics

I have a large dataset of scattered x,y,z coordinates. I am trying to use ListPointPlot3D to identify outliers in 3D. This involves generating a plot and then ...
3
votes
2answers
178 views

Bounds on random number

I have a Markov Chain Monte Carlo code that uses a chi squared function to fit some data. I am running into an issue now with getting unrealistic values for some of the free parameters in the code. ...
0
votes
2answers
2k views

Visualize Plot of a function of 3 Variables using color and contours

I would like to plot a function of three variables, say for example: $$f(x,y,z) = x^2+y^3+z^4$$ over $[-1, +1]$. I want my plot to use colors and maybe contours to make this visualization possible ...
3
votes
0answers
603 views

Using NDSolve for Integro-Differential Equations

I have a fairly complicated set of coupled non-linear integro-differential equations that I am trying to solve using NDSolve. The equations are: ...
9
votes
1answer
162 views

Creating a NearestFunction that returns an index

I use Nearest repeatedly for large data sets. For example pts = RandomReal[{-1, 1}, {1000, 3}]; Nearest[pts, {0, 0, 0}] I ...
0
votes
0answers
283 views

Performance in parameter estimation from ParametricNDSolve using varied initial conditions

I have 250 data points from a timecourse exeriment in a list, with columns specifying (1) time, (2-4) initial conditions, (5) absorbance reading. I want to fit 4 parameters (k1, k2, k3, k4) in a DAE ...
2
votes
2answers
236 views

Expanding Matrix Expressions

I want Mathematica to recognize that A.(-B.C)+A.B.C = 0 Yet FullSimplify and the like leaves the expression as it is. How do I get around this?
4
votes
3answers
297 views

Unexpected behavior of Unevaluated

Maybe it is about time I read some proper text about the main loop. Maybe I should not care (so much) about Unevaluated (as Leonid suggests). But I think this is an interesting question anyway. This ...
-3
votes
1answer
129 views

Mathematica output in ASCII or larger text size for the output?

I am trying to read the output of this code that has crosses, circles and spaces. For some reason, the output is in very-very small alphabets so I would like to get it in ASCII and/or in larger ...
9
votes
3answers
322 views

Why is this parallel evaluation with Dispatch[] so slow?

Can you efficiently parallelize this? The parallel versions are much slower than the sequential version, and I'm not sure why. Does SetSharedVariable allow ...
4
votes
2answers
177 views

How to enumerate multisets?

Given the eight-element set {1,2,3,4,5,6,7,8}, I would like to enumerate all multisets (subsets with repetition) of size n, ...
2
votes
1answer
357 views

NDSolve with vector function

(Possible duplicate yet I still can't understand.) Basic 2D revolving around origin: ...
2
votes
3answers
284 views

Using ImageTransformation[] with a lookup table

I need to transform images by ImageTransformation in a time critical application. Therefore I precalculate a lookup table lut of ...
0
votes
0answers
46 views
1
vote
1answer
230 views

How to crop graphics outside PlotRange with Show? [duplicate]

Is there an option or method to prevent Graphics from being displayed outside the PlotRange region? The problem is illustrated ...
2
votes
2answers
496 views

A Symbol with Subscript and Superscript as an Axis Label

I am trying to have the symbol $\epsilon_{9/2,4}^-$ as the axis label in a graph in Mathematica. First problem is that: when I use Subscript[$\epsilon$,9/2,4], 9/2 changes to $\frac{9}{2}$ (which I ...
1
vote
2answers
448 views

Plotting points and functions in one graphic

I have this plot: Plot[{0 x, -x, x, -Sqrt[2 - x^2], Sqrt[2 - x^2]}, {x, -3, 3}, PlotStyle -> {Purple}] Now I want to do the following. I want to plot the ...
0
votes
1answer
134 views

TextRecognize with crosses, circles and spaces results into oddities, why?

I am investigating this answer here about detecting crosses and circles with TextRecognize. I tried to solve this problem here by directly using the builtin command TextRecognize but it does not work ...

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