# All Questions

157 views

### Find lengths of contours in a ContourPlot

I am trying to find the lengths of different contours in the following plot: It is a complicated piecewise function evaluated on the unit disk. I am hoping there is an easy, generalized way to ...
221 views

### Bresenham's line algorithm

Bresenham's line algorithm is producing discretized line for given two points for purpose of plotting for example. Like that: I have to stress that I'm interested in positions, not a plot. ...
99 views

### workbench: how to see values of global variables during debugging

Consdier the following package ...
110 views

### Values (or positions) of array row elements within a specified number of positions from target value

I have the need to collect values from the rows of rectangular arrays of arbitrary precision integers, given a target element value and allowed "distance" (positions +/- within the row from found ...
778 views

### “do … while” loop equivalent in Mathematica [closed]

Have I missed something or is there no built-in which mimics the behaviour of do ... while loop? I am looking for a construct that evaluates procedure once and ...
342 views

I am the admin of a Facebook group for our year at university and wanted to graph the members of the group like you can with your own friends so we can find the isolated people and get rid of them (as ...
124 views

### Mathematica rule to express exponentials as multiplication

I'm sorry if this has been asked before, but it is a very simple question and I would imagine it shouldn't be terribly hard for someone that knows to answer. I'm essentially trying to tell ...
297 views

### Import Large Excel File

Currently, I am working on a large time series dataset, which contains 928,586 rows and 35 time intervals in columns, in excel format (.xlsx) and using Import to ...
263 views

### Find nearest distance of an interior point from perimeter

By definition, the interior point is a point inside an arbitrary region like this: In picture above, $y$ is an interior point of region. My question is how to find the distance of an interior point ...
276 views

### Recognize simple shapes in an image and color them randomly?

I have an image of polygons built from a polar function (see below). I'd like to color each triangle or quadrilateral a random color. Firstly, I'm not sure how to separate the simple shapes. ...
190 views

### About auto-compiling and performance between Do and Fold

I was investigating how Fold could improve performance vs Do. I tested the code ...
83 views

### Why do certain fractional values in TriangleWave not evaluate?

While answering another question I discovered that TriangleWave does not automatically evaluate when given certain fractional values, specifically fractions with a ...
1k views

### How to combine two vectors into a matrix by columns?

I know it may sounds idiot, but I've been looking through the document, and couldn't find a way to combine two vectors say {a, b} and ...
123 views

### Integrating a BesselJ integrand to obtain the same result as Maple 16

I would like to check the following integration: Integrate[y*Integrate[1/x*BesselJ[1,x*Exp[I*π/4]]*BesselJ[1,x*Exp[-I*π/4]],{x,0,y}],{y,0,r}] Mathematica 9.0 is ...
510 views

### Why can I still hear sound when the frequency of the periodic function inside Play is higher than the range of human ear?

We know that usually sound that is perceptible by humans has frequencies from about 20 Hz to 20,000 Hz, but as the title said, I can still hear the sound of the outputs of the following code: ...
140 views

### Random filling of L-length line with l-length segments

I have discrete L-length line filled randomly with 2-length segments so its cover line with gaps 0 or 1. So we can describe cover configuration as sequence of gaps such as {0,0,1,0,1}. How I can ...
144 views

### Why does Mathematica stop when run in the background in command line mode?

If I try to start a Mathematica script in the background from the command line, like this: math -script someFile.m & then the process gets automatically ...
328 views

### 10bits per rgb / 1024 shades of gray?

Can we display 10 bits per rgb in Mathematica? I'm using a quadro card and 30 bit monitor and can get a smooth gradient using Psychtoolbox in matlab. The following Mathematica should produce a bar ...
93 views

### Memory usage of timeseries - lists of {Integer32, Real32}

A list of {Integer32, Real32} items in Mathematica seems to use 12-times as much memory than the C equivalent array of structs. ...
73 views

### Evaluate open cell segments in a notebook

The Evaluate > EvaluateNotebook evaluates the whole notebook. Is it possible to somehow evaluate ONLY the open sections of a notebook?
500 views

### Frequencies represented in a DFT list (Fourier[])

I have a sound sample (sample rate: 44100). When I have a list l with n successive elements from the sample, ...
234 views

### Elegant Matrix Combinations

Suppose you have a matrix (mxn), simplified for illustration m= {{a, b, c}, {d, e, f}} And a set of combinations (simplified for illustration purposes but can ...
160 views

### How do I put a Monitor into CDF?

I would like to keep track of progress of a database request in an Enterprise CDF, but it won't allow PrintTemporary or ...
267 views

### NDSolve: ProcessEquations and Reinitialize with Piecewise functions

I am having trouble with using NDSolveReinitialize when the system consists of a pieceise function. If we define the ODE system ...
204 views

### How to add a graphics frame to an image without resampling

Using Inset to place an image inside a Graphics expression with Frame -> True provides a ...
237 views

### Erfi[z] expansion in Mathematica: is this a bug?

Looking at the expansion: Series[Erfi[x], {x, Infinity, 1}] I obtain -I+E^x^2 (1/(Sqrt[\[Pi]] x)+O[1/x]^2) (note the ...
279 views

### Memory efficient generation and selection of tuples

The short of this question: I need to find a bunch of n-tuples of {0,1} which do not fail to satisfy a set of (non-linear polynomial) equations, without hogging up all of my memory by trying to ...
128 views

### Multiplying expressions within a list of pure functions

Let's say I have a list of pure functions that are nice algebraic expressions: say l = {(#1 - 1)&, (#1^2 + #1)&, (#1^3 - 1)&} What's an easy way to ...
242 views

### Efficiently determining the largest minimum cost to travel from a fixed source to an arbitrary sink in a weighted graph

Let $v_i$ be a vertex in a graph $G$ with vertices $(v_1,...,v_N) \in V$ and edges $(e_1,...,e_M) \in E$ with associated weights $(w_1,...,w_M)$. Let $v_s \in V$ be specified vertex in the graph. In ...
433 views

### How to draw a Circle in a graph with Log Y Scale

I've programmed drawing tools for graph images and am experiencing a problem with the coordinates of an Ellipse on a graph with a Log Y axis. It's quite easy to work out the Y Axis coordinates for ...
108 views

### How can I test properties of a symbol without unwanted evaluation

Problem How to get the head, size, dimensions, etc. of a symbol without evaluating it? Since Mathematica does not allocate fix storage space and type to symbols it is not trivial to query runtime ...
247 views

### Simplifying the trace of a matrix expression

I have a long expression involving matrices that I derived using the NCAlgebra package. Can I simplify the trace of the expression? For example, say b is a scalar ...
123 views

### Is it possible to export equations from Mathematica to Corel with full Latex quality

I am wondering is there any possible solution to export equations from mathematica to corel x5. I was trying first to export a equations as pdf from mathematica and then to import .pdf to corel, but ...
342 views

### Checking if an expression is equal to zero

I have 6 points in $\mathbb R^3$ as follows: ...
257 views

### How can I extract the points from a ListSurfacePlot3D?

How can I get numerical output of ListSurfacePlot3D, i.e., a list of all the points, $(x,y,z)$ , used to construct the plot? Thanks to your help I now have a list of (x,y,z). But the new mesh is ...
423 views

### WhenEvent in NDSolve

How come this doesn't work as I intended? ...
167 views

### Precision of rendered Rectangles in stiff-scale graphics

The attchd graphics called chromograms represent a set of discrete-state, continuous-time - ie, discrete-event signals, generated with Mathematica 9 on OSX with a Cinema display. • Top 2 rows are ...
349 views

### List reversion inspired by Python

In python, if you wish to reverse a list, here is the trick: range(10)[::-1] => [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] Note: ...
359 views

### How to transform Do loop to more efficient codes?

I'm new to Mathematica. Here is my original program: How to rewrite the Do part? ...
99 views

### How can PixelConstrained be emulated with DensityHistogram?

This DensityHistogram doesn't display very well. Some bins are shown much larger than others and, oddly, empty bins appear to be drawn smaller than occupied bins. ...
453 views

### Connection to remote kernel can not be established - No specific error shown

I was trying to set up a remote kernel using Mathematica 8, a Debian server and a Mac OSX 10.8 client. First I configured a VPN connection between server and client and went through all the basic ...
301 views

### A GraphicsMeshConvexHull[] peculiarity

I have been unable to explain the behavior of GraphicsMesh`ConvexHull[] on the following (highly simplified) example: ...
465 views

### How do I solve N simultaneous equations for N variables?

I have a function: f[x_] := x + 31 x^3 + 5 x^25 Which I want to find an expansion for: ...
201 views

### How to make “Text” Cell which does not auto-format in TraditionalForm in-line math expressions?

This is a continuation of the previous post: How to enter textual subscripts and superscripts?. When dealing with complex in-line math expressions inside a "Text" ...
649 views

### BoxWhiskerPlot - how to specify boxes position on the horizontal axis

Let's say I have a folowing set of data: k = 1 : list of values k = 3 : list of values k = 10 : list of values I know that to make a BoxWhiskerChart I have to ...
166 views

### Feedback on my Subscript code

I have written a code, and I need a little feed back.. I want to make the Subscript distributive across (1) addition and (2) multiplication to mimic short-hand for ...
839 views

### What is the best way to make a plot complete with legends so it is exported-ready for Word?

I want to put my Plot output into an MS Word document without having to edit it in Corel first, so I want to export it ready for Word in vector format complete with legends, expressions, axes, and ...
439 views

### Fitting data to an ARProcess using FindProcessParameters

I have 50 data points that I would like to represent as an AR(4) process. I'd like to over-plot the behaivor of the estimated process model with that of the original (raw) data before I use the model ...
I need to perform a dot product on a large number of 2 x 2 matrices that I have defined to differ by even/odd subscripts (Ex: D-odd=x but D-even=y). The $\Pi$ function will not work because it does ...