4
votes
1answer
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 ...
4
votes
1answer
309 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 ...
4
votes
2answers
267 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 ...
4
votes
2answers
278 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. ...
4
votes
2answers
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 ...
4
votes
1answer
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 ...
4
votes
2answers
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 ...
4
votes
2answers
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 ...
4
votes
4answers
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: ...
4
votes
1answer
141 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 ...
4
votes
2answers
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 ...
4
votes
2answers
335 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 ...
4
votes
1answer
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. ...
4
votes
1answer
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?
4
votes
2answers
503 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, ...
4
votes
4answers
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 ...
4
votes
2answers
791 views

Solving Stochastic differential equation

How do I solve the following simple stochastic differential equation: $$ m x''[t] + \Gamma x'[t] + k x[t] = \sqrt[]{2 kb T/\Gamma)} \eta[t] $$ here $\eta[t]$ is brownian motion , i.e. Wiener ...
4
votes
1answer
161 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 ...
4
votes
0answers
272 views

NDSolve: ProcessEquations and Reinitialize with Piecewise functions

I am having trouble with using NDSolve`Reinitialize when the system consists of a pieceise function. If we define the ODE system ...
4
votes
2answers
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 ...
4
votes
1answer
239 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 ...
4
votes
2answers
281 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 ...
4
votes
2answers
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 ...
4
votes
2answers
244 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 ...
4
votes
1answer
434 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 ...
4
votes
1answer
110 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 ...
4
votes
2answers
248 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 ...
4
votes
1answer
125 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 ...
4
votes
1answer
343 views

Checking if an expression is equal to zero

I have 6 points in $\mathbb R^3$ as follows: ...
4
votes
1answer
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 ...
4
votes
2answers
428 views

WhenEvent in NDSolve

How come this doesn't work as I intended? ...
4
votes
1answer
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 ...
4
votes
2answers
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: ...
4
votes
4answers
360 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? ...
4
votes
1answer
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. ...
4
votes
1answer
458 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 ...
4
votes
1answer
303 views

A Graphics`Mesh`ConvexHull[] peculiarity

I have been unable to explain the behavior of Graphics`Mesh`ConvexHull[] on the following (highly simplified) example: ...
4
votes
2answers
466 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: ...
4
votes
1answer
203 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" ...
4
votes
3answers
658 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 ...
4
votes
1answer
167 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 ...
4
votes
2answers
845 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 ...
4
votes
2answers
443 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 ...
4
votes
2answers
2k views

How to access Mathematica license server (being outside of the local network)

This is no Mathematica-language specific question but rather a network problem, so if this is the wrong place to ask, I apologize. I am running Mathematica on Windows 7, the license manager ...
4
votes
2answers
1k views

I need to multiply a series of matrices

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 ...
4
votes
1answer
149 views

Force size in pixels of plot area excluding axes and labels

I have a matrix where each element represents a pixel. I want to plot the matrix (possibly with ArrayPlot). To suppress aliasing in the final graphic (which I will ...
4
votes
2answers
146 views

Function behaves differently inside a package than outside

I defined a function TestHead in a notebook as follows: TestHead[z___] := TrueQ[{z} == Cases[{z}, x_ /; Head[x] === avar]] to ...
4
votes
2answers
404 views

DisplayFormula not working as expected

How do I use the styles "DisplayFormula" and "DisplayFormulaNumbered"? Why is there no margin (or empty space) around the ...
4
votes
2answers
277 views

How to save a web page in mathematica?

For a given web page http://www.nytimes.com/, is it possible to save it as : first: only HTML(within css) second: more elements(include pictures and so on) just like what a browser can do. ...
4
votes
3answers
548 views

Grid - sizing and spacing problems with spanning cells

I am trying to set up a Grid with cells that span two rows and are centered on those rows, but I am having troubles with the sizing and, therefore, spacing of the ...

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