# All Questions

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 ...
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: ...
61 views

### Georeferenced bitmaps

The command Export["filename.jpg", graphic] will export the graphic object graphic to the file ...
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 ...
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.
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 ...
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 ...
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 ...
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 ...
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? ...
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: ...
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: ...
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 ...
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: ...
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, ...
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, ...
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.
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: ...
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 ...
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?
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 ...
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 ...
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 ...
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 ...
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 ...
185 views

### Isn't it possible to Pack a SparseArray?

I have the following matrix Va: ...
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 ...
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?
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. ...
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 ...
114 views

### How to apply compiled function on list

Compile function output error: How to apply compiled function on list? ...
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. ...
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 ...
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 ...
280 views

### How to un-eat memory?

Consider this code: ...
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 ...
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 ...
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: ...
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 ...
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 ...
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 ...
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 ...
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 ...
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." ...
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 ...
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? ...
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?
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