# All Questions

401 views

### What is a good coding style for setting and changing application level constants?

Background: Every application has user-definable constants. The Java language has the Properties class to handle them. Question: What is a good and re-usable coding style for setting and changing ...
460 views

### Locking a value when Manipulating variables

I'm trying to achieve something similar to Bret Victor's brilliant Scrubbing Calculator in Mathematica. By using Manipulate I'd like to change the values of the variables such that if I modify one ...
1k views

### Handling failed FindRoot calls

I want to handle FindRoot calls which did not converge (e.g "thrown" error message FindRoot::cvmit) ...
384 views

### How to distinguish between lists and values?

I have a (hopefully small) problem with some numerical integration algorithm, more specifically I want to integrate the imaginary part of a complex valued function, e.g. ...
993 views

### Efficient image Import

I have several sets of 20 images I need to import. Each time they have different categories. "Name"<>"Cat"<>"No" Electric B 1 for example. I need to create lists that contain the images ...
96 views

### How to convert arbitrary raw boxes directly into String?

This question is motivated by the recent question about searching inside of the NB files. According to the Documentation, ToString expects a high-level WL ...
119 views

### ToExpression and ToBoxes aren't inverses of each other?

Applying ToExpression and ToBoxes repeatedly to Hold[1/1] gives many ...
78 views

### Is it possible for librarylink function to be Listable like that in Compile? [closed]

We know in Compile, there is an Option RuntimeAttributes -> {Listable} which can let the compiled function easily explore the ...
297 views

### Dynamic Epicycles

Thanks to all the thorough answers and comments, I've written the following code, which builds a variable number of epicycles. However, when I apply the formula ...
4k views

### What is the difference between Mathematica and Matlab? [closed]

I am totally a beginner to Wolfram products and I'm searching for a software to solve my math problems with. Like this math problem that I've solved using $\LaTeX$ in ...
382 views

### FEM Solution desired for “Plate with orifice” deflection: Application of Boundary Conditions and use of Regions

I found the deflection of an orifice plate (circular plate with a hole) subject to uniform pressure using Mathematica's NDSolve functionality. The plate is fixed at its outer circumference and is ...
115 views

### How to make a notebook take action whenever a particular symbol is defined or redefined?

For teaching purposes, I want to create a Mathematica notebook that will "notice" when the user defines or redefines a variable or function of a particular name, so that it can check the value and ...
395 views

### How much time should one give Mathematica for an integral evaluation?

Sometimes when I do integrals in Mathematica (M), it keeps thinking and thinking and I have no idea what is going on inside M. For how long should one wait or how does one know whether M has not got ...
681 views

### How to draw a dodecahedron with each face modified to a pentagram?

I'd like to draw a dodecahedron with each face carved on the sides so it becomes a pentagram. I wonder how to start to do this kind of task in the Wolfram Language? Edit: The result should still be ...
147 views

### How to map Unevaluated over a list

I have a list {a1, a2, ...... , an}, in which all as have been initialized to a number. I want to get: ...
306 views

### How to make a binary function associative? (Or define an n-ary function?)

Suppose I have a simple function that I assign to an operator f[a_, b_] := a + b CirclePlus = f Then I want to write ...
273 views

### How can I construct a recursive pattern guard?

I am modelling binary trees in Wolfram Language by writing them as three-element lists, like so: binTree = {nodeVal, leftChild, rightChild}. It does not yet matter ...
352 views

### Computing launch parameters for hitting a point in 3D with projectile under influence of wind

The end goal of this problem is to compute functions which describe the launch parameters which are needed to hit a specified goal in 3D in the presence of wind disturbances. This is as far I have ...
252 views

### Apply ColorFunction to an Image [duplicate]

is there a faster way to change the colors of an image from grayscale to something like this: ...
229 views

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402 views

### Poincaré map for dynamic billiard

There's a very nice demonstration of dynamic billiard written by Dan S. Reznik that can be found on demonstrations wolfram(along with the code): here I was thinking whether it would be possible to ...
1k views

### Suppress extrapolation of interpolating function in a ContourPlot

I have defined an interpolating function, myfcn[x], valid on the domain x = 0 to 1.5. I am then using ...
536 views

### A topoplot function for Mathematica

Matlab's EEGlab toolbox has a topoplot function: http://sccn.ucsd.edu/eeglab/ A typical topographical plot of an EEG signal is given below: How can I reproduce this in Mathematica. I know that ...
326 views

### Dataset and string conversion, using Internal`StringToDouble

i'm trying to get familiar with the new Dataset-stuff in Mathematica 10. As it will (hopefully) provide some benefit for me, I have started to convert my app to move from list and list of rules to ...
528 views

### Why Plot3D does not accept Epilog option

I am trying to visualize 3D points with Plot3D using the option Epilog. If you check the options of Plot3D ( Options[Plot3D] ), it can be seen that Epilog is one of ...
257 views

### Evaluation in lambda function

If I have a function, that returns a function, for example: f[a_] := a^2 * # & then f[3] == 3^2 # & Is there a way ...
364 views

### Where did I go wrong with my implementation of the trapezoidal rule?

One method for doing quadrature, called the trapezoidal rule, improves accuracy by connecting the points on the curve corresponding to the points of subdivision with line segments, forming trapezoidal ...
952 views

### Getting clearer StreamPlot output

When I do a StreamPlotof a rather complicated pair of differential equations, it loses some details. For example: ...
1k views

### Manipulating plot of random iterated function system fractal

I'm generating the Sierpinski Gasket by implementing a chaos game in Mathematica. What I'd like to do is create an interactive manipulation with a slider, whereby moving it forward, plots all the ...
169 views

### Making ColorSetter work like a PasteButton

I might be missing something obvious here. I am building a palette for constructing code to make certain graphics. The idea is that my colleagues can click buttons instead of having to know the right ...
516 views

### How to plot points with uncertainties and dates assigned?

I want to plot a graph from list of points, but each point also has uncertainty assigned AND date. Without uncertainties DateListPlot works great, without dates ErrorListPlot works OK, but how it ...
390 views

### How to rename a built-in function?

I want a built-in function renamed without loss of any properties, I want the shorter name to appear in all results and to be recognized as input. Is it possible?
916 views

### Placing Manipulate controls in multiple columns

I have a Manipulate construct with a square Graphic on the left side and all the controls placed on the right side. There are so ...
9k views

### Simple ways to evaluate a derivative at a point?

The contrast in behavior between, say, f[x_] = Sin[x^2]; f'[2] vs. u[x_, y_] = Cos[x + y^2]; has always bothered my ...
212 views

### Prevent interdependence of controls

My question is probably best illustrated with this small sample code: ...
1k views

### Mathematica gives wrong answer for an integral

When I execute the following, Integrate[ Exp[-w^2 + I w^3], {w, -∞, ∞}] I get (2 E^(2/27) BesselK[1/3, 2/27])/(3 Sqrt[3]) ...
515 views

### How to create a multi-selectable setterbar with colored buttons

Background: consider the following code-snippet. ...
3k views

### Animate ParametricPlot3D for two different parametric equations

I want to write a computer program to generate 3-D plots (with x-y-t axes) to demonstrate the evolution of the two missiles in the following case: i. $x = 100t$, $y = 80t-16t^2$ for $0\leq t\leq 5$ ...
2k views

### Simplifying nested If statements

Consider : list = {100,102,103,99,106,107,104,112} I want to consider, extract only the "big moves" of that time series. In this case the moves bigger then 5 ...
296 views

### Diagonals of a regular octagon

We had a little activity after school today and one of the questions was: All diagonals are drawn in a regular octagon. At how many distinct points in the interior of the octagon (not on the ...
160 views

### How does thing[“property”] syntax work?

Many builtin "things" support the (usually undocumented) syntax thing["property"], and usually the available properties can be listed using thing["Properties"] (thing["Methods"] might work too). ...
424 views

### Using Greek $\LaTeX$ fonts

I want to use the $\LaTeX$ font in graphics. For text/numbers, this is easily done by FontFamily -> "CMU Serif" (on Ubuntu) like this: ...
320 views

### Dynamic list in which the sum of the elements is invariant under changes to the elements

2nd Update Here's a snapshot of a graphical user interface I'm thinking. I hope this could be self-explanatory and demonstrate the functionalities I mentioned in the 1st update. Thank you all! ...
422 views

### How do I plot my country map with weather data stations?

I've tried this code, but I can't plot the coordinates in my country map. ...
385 views

### How can i construct a 3D surface pass through a curve defined by formula and some other controllable points?

For example, If a have a curve defined by x^2+y^2=1 and z=0, and some isolated points having z coordinates, Can I construct a 3D surface passed through? It's better if I can change the surface shape ...
730 views

### Collision detection algorithm (discrete) with sweep and prune algorithm

For a more complex collision detection approach, I need an efficient (aka fast) algorithm to prune the elements by using boundary boxes. A classical algorithm is the so called sweep and prune (SAP) ...
332 views

### How to use a compiled function in numerical optimization

I'm trying to wrap my head around function Compile. So, this is a spin-off question from: a previous question on using compile[] correctly. I have a function that ...
171 views

### DeleteMissing level spec confusion

Given: titanic = ExampleData[{"Dataset", "Titanic"}] Why does this correctly delete Missing[] elements: ...