# All Questions

519 views

### how to read in a file in the same directory?

Now I am writing a small package. I have written several files and put them in the same directory. And some files need to read in or include another file in the same directory. But when I simply write ...
1k views

### Why does Export drop namespace prefixes in the exported XML file?

I am trying to generate an Excel-compatible XML file from Mathematica. First, I created a test XML file by saving a Microsoft Excel workbook as "XML Table". Then I ...
833 views

### Plot3D in Mathematica: how to plot in presence of parameters

I realize I the earlier question was ill-posed. To clarify: I am trying to find the values of $A$ and $B$ that will maximize a function f on the domain ...
399 views

### Retrieving duplicates from nested list

Consider the following: data={{1,a},{10,a},{5,b},{4,c}}; In my case duplicates are defined when for {x1,y1} and ...
563 views

### simplifying $\frac{\log x^a}{a} = \log x$

If one makes the assumptions $x>0,a>0$, then $\frac{1}{a}\log x^a = \log x$. Thus, in Mathematica, Simplify[1/a*Log[x^a], {a > 0, x > 0}] returns ...
467 views

### CDF and personalized style

I recently created a custom stylesheet. I then created a notebook with the new style, confirmed that the notebook had adopted the style, and then saved a copy in CDF. But when I opened the CDF in ...
104 views

### Monitor function doesn't show continious change of values

Bug introduced in 10.0 and persisting through 10.3 Mathematica version: 10.2 Monitor[i = 0; While[i < 100, Pause[0.1]; i++]; i, i] The above code is from ...
328 views

### Coloured image transformation in pointillism

I would like to transform an image (a photo for example) into a set of single colour circles with fixed but adjustable diameter (bigger than the pixel size), into a kind of pointillism. The number of ...
231 views

### How to efficiently get breakpoints of piecewise functions

Setting. Imagine that we have several arbitrary linear functions in 2D that can be changed manually (say, slopes are parameters). Their Min (or ...
100 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 ...
239 views

### How to write an operator that acts on pure function (to give another pure function)

I would like to write an operator oper that acts on a pure function f with an undetermined number of arguments, with the syntax ...
322 views

### Appending and Prepending columns to a dataset in 10.0.2.0

fixed in 10.1 (windows) I just experience a problem in prepending columns to a dataset. I did this a hundred times in 10.0.1.0 - no problems. Now it seems as if it is only possible to ...
253 views

### Drawing a graph with vertex avoiding edges? (Handling vertices that must be colinear?)

I'd like to draw something like the following graph: ...
216 views

### Understand MeshFunctions with Intercepts

Bug introduced in 7.0.1 or earlier and persisting through 10.0.2 or later While I've been thinking about this question, I tried to visualize the Intercepts. I use three snippets, actually snippet ...
618 views

### Plotting a moving ball for projectile motion with animate

Here is my code for plotting an orbit. What I want to do is have the "planet" shown as it orbits in the simulation. Can anyone help with this? ...
887 views

### How to find all data points within closed curve

I want to find all data points inside curve as given below: ...
744 views

### How to fix this memory leak

I am using halirutan's code in this thread to unflatten a list. It works very well but the problem is that the Module's local function f is not deleted when the ...
531 views

### How to make a point's position time-dependent given a formula for the next step?

I've made a program that is just some points on a plane. Red points are cops and green points are robbers. Each point has a vector indicating where it is going to be in the next step of $t$. Right now ...
251 views

### How to get all possible orderings (equal ranks allowed) for given set of $N$ objects?

Hope there is a solution besides the tedious generation of nested loops. (Trying to avoid reinventing the wheel.) Here is an example with $N = 3$ objects. There are $13$ needed orderings (first ...
212 views

### How to join held Lists?

Let's say I have a = Hold@{2+2} b = Hold@{4+4} How can I get Hold@{2+2,4+4} ie join the two held lists ? More ...
548 views

### Export list elements each to it's own page in a multi-paged PDF document

I have a list, myList, of let's say 20 (different) objects myList = Table["object", {20}] I know would like to export every ...
214 views

225 views

### Wrapper for inexact numeric complex numbers that maintains polar form

Related question: How can I convert a complex number a+b I to the exponent form A Exp(I phi)? Mathematica insists on displaying complex number in form a+I b when ...
1k views

### Failed to connect remote Mathematica kernel using J/Link

I'm trying to connect to a remote Mathematica 8 kernel (on a Windows machine) using J/Link. On the client machine, I put the JLinkNativeLibrary.dll file in ...
1k views

### Grain(Particle) Size Distribution (PSD) Analysis with Mathematica

I would like to do an analysis of the grain size distribution of a Monte Carlo Grain Growth simulation I implemented based on the nice example by Rituraj Nandan (see Link). The result of this ...
358 views

### How to make the docked cell and the navigation toolbar in the Slide Show?

I have a notebook with a docked cell displaying a banner with some graphics. When I convert this notebook to the Slide Show the banner is nicely displayed on each slide. But the Navigation Toolbar is ...
207 views

### Prevent interdependence of controls

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

### How to rotate TickMarks in DateListPlot?

Is there a way to rotate TickMarks in DateListPlot to avoid overlap, eg: Part of the code used to generate this is: ...
415 views

### Combining and aligning “chart” type graphics with regular plots

Is there an easy (recommended) way to align regular plots (e.g. ListPlot or Plot) with chart type graphics (...
457 views

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

Background: consider the following code-snippet. ...
327 views

### Why can't D[] be used in place here? [duplicate]

Possible Duplicate: General::ivar is not a valid variable when plotting - what actually causes this and how to avoid it? Beginner question: Why can't I use ...
364 views

### Revert FullForm-ed text to prettyprinted

Sometimes strings in a notebook/package file end up garbled due to some unknown/unintentional conversion of the expression/cell/notebook. I could not find a way to revert such unreadable text to its ...
422 views

### Random sampling of multiple integers with constant sum

I want to build a model of 40 geological layers, assuming each layer has equal chance to be one of the four types of rocks and the four types of rocks have equal chance to appear in any layer. The ...
193 views

### Mathematica-exported PDFs placed in Illustrator documents keep disappearing

This question is regarding interoperability between Adobe Illustrator and Mathematica. Illustrator has a File → Place... function which can insert complete figures inside Illustrator documents. ...
187 views

### Speed and the MapThread function

Can anyone help explain why MapThread is so slow in this simple case? ...
230 views

### How can I stop Mathematica from re-arranging formulae in TraditionalForm?

Let's say I have a sample formula, for example (Abs[x]/(-(2 - \[Kappa]) - 5))/(Binomial[a, b]/4) or something like that. I can of course typeset it to a limited ...
297 views

### What is shorthand way of Reap list that may be empty because of zero Sow

Sometimes because of conditionals, you cannot guarantee that Sow will be called at least once. Reap[Sow[1]][[2,1]] results in ...
235 views

### Simplify 2D polyhedral Regions like Interval

I don't think there's a built in "RegionSimplify" for polyhedral Regions and derived akin to how Interval automatically simplifies its argument expression: ...
193 views

### Weird output of DistributionChart

I have a larger data set and want to display it using DistributionChart. ...
146 views

### Choppy curves with Manipulate [duplicate]

While manipulating the slider in Manipulate[], I experience choppy curves. These do however render correctly after letting go of the slider. The same phenomenon occurs when pressing the + or - button ...
146 views

### Return value of Reap when using tags

I've noticed a behaviour of Reap that I don't quite understand yet. Suppose I want to Sow several values during a computation. ...
151 views

### Fractions formatting in Column / Grid

Fractions are squished in GridBox: ...
267 views

### How to deal with too much recursion

I have put together a very simple climate model based around four equations which define the state at time t based on time t-1, ...
158 views

### How to simplify my expression to the style of “a+b*I”?

How to simplify my expression to the style of "a+b*I"? Expand[(E^(I θ) (-1 + E^(I n θ)))/(-1 + E^(I θ))] ...