# All Questions

284 views

### Is it possible to use Compile on a function with optional arguments?

My Mathematica is a little rusty, so apologies in advance. I think my problem is quite simple, but I can't seem to find the answer on my own! Simple example : ...
200 views

### How do I write a function that can be used in a rule to modify both sides of an equation? [duplicate]

I sometimes need fine grain control over equations in Mathematica in order to help me understand how to solve a problem manually. A greatly simplified example of a session might be something like ...
513 views

### Distorted graphics when using custom ticks and AspectRatio -> Full

Bug introduced in 7.0.1 or earlier and partially persists through 10.0.1 or later I am having a problem using custom tick specifications along with ...
1k views

### Finding the square root of a random number with Newton's method, using While/Do/For loops?

I am trying to construct a program that will find the square root of a number, using Newton's method, which is $$x(n+1) = x_n- f(x) / f'(x_n)$$ The number, will be a random number, generated by: ...
114 views

### Strange double evaluation using MorphologicalGraph

(MMA 9.0.0 on Mac OS/X 10.8) Please consider the following snippet (this is as SMALL as I could make it -- my attempts at making a smaller repro-case eliminated the effect that I am investigating) ...
168 views

### Efficient way to give symbolic elements symmetry

I have a symbolic expression that represents a set of operators. These operators have quite a bit of symmetry to simplify expressions: ...
278 views

### Exclude Sections/Subsections/… from evaluation

I'm working on a large notebook and I want to exclude some sections and subsections from being evaluated when I evaluate the whole notebook. Is there a way to exclude specific sections or ...
493 views

### NIntegrate Error-Estimate Question

When I do some complicated 4-dimensional integral numerically, Mathematica tells me its estimate for the value of the integral, and its estimate for the value of the error in the calculation. The ...
2k views

### How to make plot with frame and two different scales on the x-axis (CMB power spectrum example)

Let us take CMB spectrum as an example. I get data of $C_l$ as a function of multipole moment $l$. Also, multipole moment is a function of angular scale. The question is: how to make a plot with a ...
1k views

### Why doesn't Mathematica make an obvious simplification?

I am doing some calculation with summation and the Kronecker symbol. Here are my steps : ...
2k views

### Product of Fibonacci numbers using For/Do/While loops

I want to find the product of the first 20 Fibonacci numbers (the fibonorial). I want implementations using While, Do, and ...
432 views

### Piping and Replacement

I haven't been able to figure out how to use piping with certain functions. Specifically, I would like to apply a replacement at the end of a pipe, like the following: ...
2k views

### Faster way to convert real strings into numbers [duplicate]

Working with big files, I have to convert some numbers that are in string format into real MMA numbers. I know that I can use ToExpression but it's slow when ...
251 views

### Grid generation around airfoil from data

Here is the data http://wikisend.com/download/405620/datapoints.dat I have (x,y) data for a grid around an airfoil and I am trying to figure out how I can draw radial and polar lines for the grid to ...
255 views

### How can this DivisorSigma code be made fast?

Since Project Euler problems are now fair game for questions I have a question of my own. A certain problem* states: For a positive integer n, let σ2(n) be the sum of the squares of its ...
578 views

### Importing data sets from plain-text files and performing operations on them

I am working with a lot of daily weather files in the txt format. I need to calculate a daily quantity from each of them, e.g., daily light intensity, which ...
664 views

142 views

### Get DownValues that do not involve patterns?

Say I have a function with a few definitions that also implements memoization: f[x_] := f[x] = x^2 f[x_, y_] := f[x, y] = x^2 + y^2 I then apply the function to ...
541 views

### Best way to modify values in a list of rules?

Recently I had to solve a problem similar to this: Let's say I have a list of list of rules ...
188 views

### Evaluation order of Button[]'s action

it looks like it should be well known issue but I haven't found answer anywhere. Please tell me why the result (after clicking) of this: ...
434 views

### Why use Column with Rows instead of Grid?

In general, what are the advantages of using Grid versus a combination of Column and Row? Is Grid better in some situations but not others? For example, is there any reason why one would do this: ...
694 views

### How to label the Vertex and, or Edge labels with their weight

I noticed that the Mathematica 9.0 documentation only mentions the usage of "Name" to label the vertexlabel or edgelabel in the Graph. Is there an option to use the Weights automatically just as ...
255 views

### Forming Cone with Tube fails to work in version 9.0.1

I use two different radii in a Tube expression to draw a cone. I know for a fact that this worked in Mathematica 8, but when I reevaluated my code in versio 9.0.1 ...
5k views

### Image processing: Floor plan - detecting rooms' borders (area) and room names' texts

Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans. The ...
2k views

### Compare C++ Standard Library's Mersenne Twister with Mathematica's Mersenne Twister

The C++ standard library does contain a set of random distribution classes, among other things a Mersenne Twister engine. What I'd like to do is to generate the same random number distribution, using ...
86 views

### Plot axes invisible when projected

When I save plots made in Mathematica in PDF format and then insert them in a presentation (e.g., in Powerpoint), the plot axes are invisible in the picture created by the projector. Is there a way to ...
873 views

### How to clear parts of a memoized function?

I have a function of two variables, e.g.: f[a_, b_] := f[a, b] = something f[a - 1, b - 1] etc With the above code I used the concept of memoization to speed up ...
224 views

### Is there a way to teach integrate new solutions?

I have an integral which I can solve, but integrate cannot: ...
149 views

### An issue with formulas typesetting in Grid & Column

I tried to construct a small sheet with text and equations presented in a convenient publishing form, using Column: ...
265 views

### How do I get a list of allowed values for an option?

When using Mathematica how can I get a list of the allowed values of an option? As an example I can use the Options command as follows - ...
296 views

### EventHandler {“MouseDown”, 1} with PassEventsDown -> True not working as expected

I want my EventHandler to respond only to left mouse clicks and pass the right mouse click to the built in event handler. I have tried ...
735 views

### How to play microtonal music using Mathematica?

I am trying to model microtonal music using Play. I have only partial success because it takes such a long time to make some sound. Could you please have a look ...
403 views

### Integrating hat functions

I am trying to integrate a hat function for a project that I am doing and have found a method to do so but I find it sloppy. Currently I have the basis function ...
328 views

### How can I get WhenEvent to recognize criterion I specify?

Using NDSolve I want to solve a differential equation till a quantity which is a function of the dependent variables reaches a certain value. My functions and criteria are complicated, but I am able ...