# All Questions

99 views

### Detect Messages within an expression without losing the return value?

I know that Check[expr,failexpr] is a mechanism to catch messages. The problem with it is that if a message is generated within ...
372 views

### Association and rudimentary object-oriented programming

Doesn't Association provide us rudimentary object oriented programming via constructs like ...
99 views

### Change of basis for a rank 3 Cartesian tensor

I have a Cartesian tensor $\chi_{ijk}$ and I want to express the elements in terms of a new basis to get $\chi_{ijk}^\prime$. The transformation is represented using $a_{ij}$. The tensor transforms ...
37 views

### Visualise sets giving some relations on those sets

I'm not very experienced with wolfram, but I'm searching for a function that can basicly do the following. Giving some sets $A,B,C$ and some relations for example $B \subset A$,$C\subset B$. I would ...
91 views

### Understanding the use of GradientOrientationFilter to achieve a “brushed” effect

I'm trying to recreate in Javascript a piece of code that appeared here on Mathematica, specifically in this answer. The user Simon Woods suggested an amazingly efficient way of drawing lines over ...
347 views

### Changing the x-axis for ListLinePlot with more Lists

I'm fighting with a seemingly very simple problem: I have two lists of data, and want to plot them with ListLinePlot. The two lists are only data-points, therefore ...
193 views

### Finding relevant parts in XML document

My question is about a XML document and finding parts of strings. test = Import["C:\\Users\\filename.xml", "XMLObject"] This gives the following output: ...
122 views

### How to plot multivariate tabular data

Suppose I have tabular data usual for numeric packages: T = Table[{x, Sin[x], Cos[x]}, {x, 0, 1, 0.1}]; T // TableForm Now I want to plot ...
130 views

### defining Associated Stirling numbers of the Second Kind

First, I'm new to Mathematica. Spent my undergraduate programming with Maple and my computer crashed and I lost it. Fortunately, my university offers free Mathematica downloads to students, so here ...
153 views

### RegionMember with some tolerance?

Can I specify some tolerance for the new geometric-computation function? RegionMember[Line[{{0, 0}, {1, 0}}], {.5, 0}] (* True *) While: ...
59 views

### Shortcut to erase the line one writes on, equivalent to Ctrl+k for pico? [duplicate]

Every time I make a mistake (and I mess up quite often, since I'm new here), I loose time having to use the mouse to delete the traces of my mistakes: the blue vertical lines with the following ...
41 views

### Disable locator-removal in LocatorPane

is there a way to DISABLE the ability to remove points with ALT-click (APPLE-click) from a locator pane? I'm writing a code that allows users to manually label objects in an image by connecting two ...
93 views

### Request for clarification of Eigensystem::eivn message

What causes the problem of "two eigenvectors associated to one single multiplicity eigenvalue" that I am experiencing? After several transformations to simplify an unwieldy matrix, I end up with the ...
308 views

### What is the best way to flatten a linked list with lists as values?

By following the advice on this site I have ended up with a linked list like the following: acc = {{1, 2}, {{2, 3}, {{3, 4}, {{4, 5}, {{5, 6}, {}}}}}}; This was ...
166 views

### Recognizing Matching Colors in a Game Grid from a Camera Image

I am relatively new to Mathematica, having taken my first serious dive into it this week. As a fun project to teach myself some of the basics, I've come up with a goal of optimally solving a game ...
40 views

### How i can extract a single layer from a SHP file? [closed]

I just import a SHP file that have a series of layers, how can i get just one if i know the name of it?
316 views

### Not able to get a solution to a Lagrange Multiplier Equation

I assigned several constrained optimization problems to my calc IV students to solve with Mathematica, but this one is being stubborn. The function to optimize is: f(x,y,z) = y Exp[x-z] with the ...
206 views

### Getting the Cumulative Distribution Function of f(x) from a dataset of x

I've a data set $\mathcal{X}$ which consists of randomly generated numbers. Let's say for example data = RandomVariate[ExponentialDistribution[1], 10^4]; My aim ...
160 views

### MatrixPlot provides wildly inaccurate PlotLegend?

I noticed something weird with MatrixPlot's PlotLegends -> Automatic behavior- here's a minimal example: ...
67 views

### Error with comments inside and expression

I found this strange parsing error with comments inside of an expression in Version 7. And example is {{1, x}, {1, y} (* {1, z (= 5+6)} *)}; It occurs depending ...
233 views

### Extracting Coefficients from a List of Sines

I want to extract the coefficients from the following list: list={16.2219 Sin[16.2219 t], 6.60924 Sin[6.60924 t], 13.927 Sin[ 13.927 t], 2.91309 Sin[2.91309 t]} ...
253 views

### Legend placement explanation

Could anybody explain, how the coordinates in Placed influence each other? ...
242 views

### How to write complex function definitions at run time?

(Posting as a self-answered question to share a technique I discovered) In a certain project, I have many function definitions in which all parameters should be optional and come with default values. ...
200 views

### Problems with NDSolve and partial differential equations of several variables

Suppose we have the following partial differential equation: $$0 = \frac{ \partial w }{ \partial \tau } + \left( w + \sqrt{ h + \beta } \right) \frac{ \partial h }{ \partial \chi }$$ where $w$ = ...
172 views

### Why is my Fourier transformed matrix rotated?

After Fourier transforming and shifting the zero frequency of a matrix, my outcome is rotated by 45 degrees from what it should be. Can anybody spot why? ...
51 views

### Error messages from NIntegrate [closed]

I've been trying to work on some integrals (Actuarial Science, for those interested) but somehow this always returns an error for me. ...
78 views

### Undocumented options for NSolve

There are many undocumented options in Mathematica's official documentation. Is there a tutorial, or a reference somewhere, that explains in detail the undocumented uses of ...
35 views

### How to plot morphological stripe near the mouse-clicked position in an image? [duplicate]

I tried to use EdgeDetect and MorphologicalComponents to get the image edge elements. When I clicked on an image, I want the edge element nearby to be highlighted or plotted. Here is my code. Two ...
729 views

### What is special about 70.329862 and InputField and Number and Dynamic?

Is this a bug (happening in V9 and V10 Windows, Linux) or not? It only happens for certain numbers and you need Number in InputField. ...
132 views

### Can you compute more terms in this sequence?

I am trying to identify a sequence related to the von Mangoldt function matrix. Since I believe/conjecture that the columns in the matrix have period lengths as in this sequence b: ...
113 views

174 views

### How to align rotated BarChart labels? [duplicate]

I'd like to use long text labels for a simple BarChart, but when I apply a rotation to label strings with different lengths the end of the text is no longer aligned ...