0
votes
1answer
97 views

Pure function in Nest

I can't figure out what I'm doing wrong here: Table[Nest[# + 0.1 * -i * #^2 &, 2, 1] , {i, 0, 0.5, 0.1}] (* {2., 1.96, 1.92, 1.88, 1.84, 1.8} *) The problem ...
1
vote
1answer
286 views

dynamically set fit parameters and models with FindFit

I want to fit a gaussian profile by setting some values dynamically, but FindFit returns an error and i can't see the problem. with a given gaussian: ...
2
votes
0answers
61 views

Georeferenced bitmaps

The command Export["filename.jpg", graphic] will export the graphic object graphic to the file ...
2
votes
2answers
282 views

Can Mathematica identify formulae or sequences of numbers?

Can Mathematica suggest what a formula means? For example if I input $$\sum_{i=0}^n i$$ can it infer that this is a sum of integer values from $0$ to $n$? Or if I enter $0,1,1,2,3,5,8,13$, can ...
-1
votes
1answer
105 views

Button with for loop

How can I call a function that has a for loop inside a button? If I just write button[{"name", function[]}] nothing happens.
13
votes
2answers
438 views

How to simulate the true reflective movement of a particle bouncing around in an ellipse?

Please help me to simulate the movement of a particle inside a region with elliptical walls such that particle is reflected from the walls and continues to move. A friend was able write code to ...
0
votes
3answers
408 views

Plotting Voxel in mathematica

I am developping a 3D reconstruction application. I recuperate the voxels coordinates (the coordinate of each voxel) of the object that I need to reconstruct. Each voxel have a dimensions like this ...
1
vote
1answer
280 views

Feynrules -> FeynArts issue

When I try to use model files generated by FeynRules in FeynArts, I always get errors of this form Coupling definition in ...
4
votes
3answers
316 views

First 10 digits of $\pi$ without rounding

I need to have $\pi$ with an accuracy of $10$ digits. My first guess would be N[Pi, 10] However, this rounds to the last digit instead of just chopping of any ...
10
votes
4answers
275 views

No response to an infinite limit

Trying to compute this limit, things seem to get frozen, even for hours. What would you recommend to fastly compute it? ...
1
vote
1answer
1k views

How to find the area between two curves

Find the area between y = 1 - x/π and y = Sin[x]. Here is what I have typed in so far into Mathematica: ...
1
vote
1answer
107 views

Specify positions in a SparseArray using patterns with functions

I spent some time trying to figure out what was what was making so slow the calculation of the following array(actually this is only a SUPERsimple toy model): Input to the array: ...
4
votes
3answers
200 views

How to compile a diagonal array efficiently?

For example, if we use some functions defined prior to Compile, we usually have the main evaluators in the compiled codes, pointing to the definition of the ...
1
vote
1answer
82 views

Multilpe matrix (mxm) and vector (n), wich are unequal, so get a (three dimensional matrix) mxmxn matrix

For example I have this matrix: mk = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}} and I'd like it to multiple with this: ...
3
votes
0answers
78 views

Efficient storage of Kronecker sum of circulant matrices+diagonal matrix

I have a square matrix of the form $$M=D+\overset{N}{\underset{n=1}\bigoplus}R_n,$$ where $R_n$ are circulant matrices, $D$ is a diagonal matrix and $\oplus$ is Kronecker sum. Its size is quite big, ...
0
votes
1answer
164 views

NMinimize stops with no more memory?

I am using NMinimize function for simulation based optimization. So my objective function is a simulation that runs for every combination of variable values evaluated by NMinimize function. However, ...
8
votes
3answers
311 views

Find the best parallel lines to a given data set

I have a set of data in an uptrend. I would like to find two BEST parallel lines to contain all the data but I don't know how to approach it, anyone can help ? Thanks.
3
votes
2answers
558 views

Plot3d: How to color a surface according to the slope of the surface?

Here is my approach, for an example surface function: surface[x_, y_] := Sin[x y]; The normal vector of a point in the surface is computed as: ...
13
votes
1answer
344 views

Formatting Excel Borders with .Net

I have various tables generated in a Mathematica application and need to export this to MSExcel formatted in a specific way. The ...
10
votes
1answer
590 views

Scheduling Mathematica scripts to run from a command line [duplicate]

I want to run Mathematica "jobs" on a daily/weekly basis to do system maintenance and as part of daily processing operations. What is the best way to do this?
0
votes
2answers
106 views

Code for sum of exponential divisors function

Consider $n = p_{1}^{a_1}\cdots p_{r}^{a_{r}}$. An integer $d = p_{i}^{b_{i}} \cdots p_{r}^{b^{r}}$ is called an exponential divisor of $n$ if $b_{i}$ divides $a_{i}$ for every $1\leq i \leq r.$ I am ...
1
vote
1answer
181 views

How to construct a graph from a list of edges

I have a list of pairs of numbers, representing connections between objects in the real world. Each number is the identifier of an object, there are gaps in the range from the smallest number to the ...
0
votes
0answers
41 views

Manipulate freezing on large calculations [duplicate]

I have a sum that ordinarily takes some time (2 - 3 seconds) to calculate. When I put it into a manipulation though, it becomes very temperamental. It will work on some very small calculations, but ...
3
votes
1answer
176 views

Manipulate with formatted output

I would like to have 4 output fields for something like the following: Manipulate[ n*x n/x n + x n - x, {n, 1, 10}, {x, 1, 10}, ControlType -> InputField] but ...
3
votes
1answer
111 views

Opposite function to Normal

Is there any function opposite to Normal? For example, let as say that I have an SparseMatrix A, then, let as say that for convenience for a certain operation like Packing, I convert it into an Array ...
4
votes
1answer
185 views

Isn't it possible to Pack a SparseArray?

I have the following matrix Va: ...
1
vote
1answer
820 views

shooting method and stifness problem for NDSolve

I'm trying to solve numerically the following differential equation: 1/r[x]^5 + k/Sqrt[1 + r'[x]^2] - (k r[x]r''[x])/(1 + r'[x]^2)^(3/2) == 0 I can set boundary ...
0
votes
1answer
203 views

How to draw the plot of a function in the complex plane? [duplicate]

I'm new to Mathematica, and I was wondering how to plot $x^n$ in the complex plane. Is there a dedicated function for this purpose?
6
votes
2answers
328 views

Memory management and speed for Fast GCD

Let's say that we have some $300\,\text{K}$ digits (arbitrary function) and want to trial factor with $100{,}000{,}000$ first prime numbers. ...
1
vote
0answers
135 views

What is the Missing code in this Wolfram Blog article?

Here's a very cool Wolfram Blog Article with incomplete code, that can apply the Droste Effect to an image is various interesting ways. Copying this code, in the journal doesn't provide a working ...
1
vote
1answer
114 views

How to apply compiled function on list

Compile function output error: How to apply compiled function on list? ...
11
votes
1answer
497 views

What is the proper way to verify that two expressions are equivalent?

First of all, it appears to me that $$\left|\frac{1}{x} + x^2\right| \Leftrightarrow \frac{|1 + x^3|}{|x|}$$ is true. I don't know why, but my attempt to verify it in Mathematica failed. ...
8
votes
0answers
290 views

How does Mathematica find a series expansion of expressions containing logarithms when there is a singularity at the expansion point?

I am looking for a good approximation to a function containing logarithms, especially at values close to zero. When I used Mathematica's Series command I found ...
2
votes
1answer
251 views

How can I create an interactive application that accepts data and and plots it?

I have some code in Mathematica which shows a colored plot, where the coloring depends on data values. I would like to make this into an interactive application that accepts two inputs: data, a list ...
8
votes
2answers
280 views

How to un-eat memory?

Consider this code: ...
12
votes
1answer
498 views

What is available for editing Mathematica source code with Emacs?

I can find several Emacs libraries for Mathematica, but I'm not aware of a clear favourite, a definitive list, or of a library which is actively maintained and developed. None of these appear to be in ...
0
votes
0answers
43 views

Mathematica how to plot objects with labels in 3D plot [duplicate]

The following code plots 3 cuboids, each with a label at the lower left vertex. The label is meant to be part of the cuboid object. Yet, since Text[] is used to ...
4
votes
2answers
209 views

Prevent Grid from resizing images

Aligning my images in Grid causes one of them to become smaller, despite specifying each of their sizes with ImageSize: ...
0
votes
2answers
133 views

Getting new symbols into Mathematica

What is the easiest way get new symbols into Mathematica 9? For example I want to be able to write the Symbol \mathfrak{A} that you have in Latex. I know that ...
0
votes
0answers
154 views

NonlinearModelFit with multiple parameters

I am now trying a slightly more complicated model which actually consists of finding the parameters of 2 particles in an Image (I attached an Plot of an image). Although I put very good initial values ...
5
votes
1answer
140 views

Setting options of expressions similar to using SetOptions on objects

Introduction I often have the problem that in an expression, I want to change an option. If we are sure the option is not present, we could simply use ...
5
votes
1answer
342 views

What is missing in this Mathematica Journal Article?

So I had been looking to solve a little tiling problem and Google turned up this Mathematica Journal Article and I noticed the code was both incomplete and incorrect, so... My Question is, What is ...
2
votes
1answer
608 views

Arnold's problem #8

The famous Arnold's problems (see http://www.math.upenn.edu/Arnold/Arnold-Trivium-1991.pdf ) are aimed at the strong graduate and postgraduate students of the top universities. I find it remarkable ...
2
votes
1answer
90 views

WeatherData function problem: “NonMetricValue” returns undated list of values

In the WL example below, WeatherData[] returns an undated list of values when I add the annotation "NonMetricValue." ...
1
vote
2answers
262 views

What's the best way to generate all the upper triangular matrix whose singular values are given?

For example, given $\lambda_1 = 1, \lambda_2 = 2, \lambda_3 = 3$, what's the best way to generate all the upper triangular matrix ($3\times 3$) whose singular values are $\lambda_i$? Note:Given a ...
2
votes
0answers
82 views

What are the limits of the Prime-functions? [duplicate]

Will Prime and PrimePi test up to 3 * 10^12? Where can I find the limits for these funtions? ...
4
votes
0answers
223 views

Call Haskell from Mathematica and return the results inside Mathematica

I would like to learn Haskell using Mathematica's environment. I know there is the RLink protocol. Is there a similar protocol for Haskell?
2
votes
1answer
76 views

is there an option for FitResiduals in FindFit?

I know this option exists in NonlinearModelFit and probably in other fit models as well but for some reason the best result i get is with FindFit. Regards Doron
4
votes
1answer
243 views

Plot a cone in spherical co-ordinates

As we all know in spherical coordinates a function phi = π/3 gives us a cone. The cone makes an angle of π/3 with the imagined ...
2
votes
1answer
85 views

Convert Integer to Numeric with Replacement rules

I have a long list of triples, each looking something like {AGO, 1988, 2345.23}. Some of these, however, have an integer in the third spot, like this: ...

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