2
votes
2answers
131 views

The i-th element of a permutation [duplicate]

I am trying to run something of the form ...
1
vote
1answer
84 views

Attaching functions to movable locators

I'm trying to create a manipulate plot showing the electric field due to a collection of point charges. At the moment I've created such a plot which allows the x and y positions of each charge to be ...
2
votes
1answer
93 views

How to tell NDSolve about known relations of the exact solution

The solution to this system of differential equations: ...
5
votes
0answers
167 views

Convex hull of a large data set of 3D points

I recently needed to deal with a large data set of 600.000 points in three dimensions. My task was to find a convex hull for this data. I have Mathematica 10, so I could use the function ...
8
votes
3answers
361 views

Torus triangulation

I'd like to plot something similar to this but with a triangle instead of a pentagon. Also, I'd like to triangulate the faces, that is, to insert the diagonals for each face of the 3 prisms used. In ...
11
votes
4answers
794 views

To inscribe a circle in a given triangle

I am trying to to inscribe a circle in a given triangle but it isn't working. I've used GeoGebra with this construction and worked but as I'm new to Mathematica I am missing something. It can't be so ...
2
votes
0answers
80 views

Gradient Filter Function

I am trying to understand EXACTLY what the GradientFilter function in Mathematica is doing. As far as I can tell, it appears to be doing a convolution of a first derivative of a Gaussian with the ...
7
votes
2answers
207 views

Export Grayscale Bitmap

I have a grayscale (one channel) image in Mathematica. How can I export it as a grayscale Bitmap? Every single option I tried so far does not have an influence on the Bitmap exported using ...
4
votes
1answer
203 views

ArrayPlot copied to PDF shows blurred mesh

Certain (but not all) images displayed in ArrayPlot, and then copied to PDF, show what appear to be fuzzy mesh lines in white areas. An example is shown below. I ...
5
votes
2answers
122 views

Customizing display of partial differential equations

I am manipulating partial differential equations symbolically, and would like to get the easily readable form $\rho \frac{\partial v}{\partial t}$, leaving variables implicit. Based on suggestions ...
1
vote
1answer
109 views

How to get matching starting dates for different `FinancialData` properties? [closed]

Why do the "Return" and "Volume" outputs of FinancialData differ? Consider the following ...
11
votes
5answers
604 views

How to combine one or more rotated graphics objects?

I wish to produce an image with more than one composite graphics objects which have been modified using Rotate. I feel this should not be difficult, but haven't yet found a solution. A simple example ...
5
votes
4answers
121 views

Passing a variable messages list to Quiet

I'm trying to build a Verbose option into some code but I'm having trouble passing to a Quiet statement a variable list of which messages I want to suppress. My ...
1
vote
1answer
188 views

Appending to $Assumptions - Error “Nonatomic expression expected” [closed]

I need to use lots of assumptions in my code. Therefore I put them into the $Assumptions variable. When I do it like this, all is well: ...
10
votes
2answers
228 views

Why isn't Lookup treated like other symbols?

With Mathematica 10, I wanted to overload Lookup using TagSetDelayed, but it doesn't work. For instance, if I define two objects ...
5
votes
1answer
171 views

Installing R packages using RLink on Mac OS X

Is there any updates regarding installing CRAN packages via RLink in Mathematica 10 on Mac OS X? Or are we still stuck with the base R package and that's it? I was able to point to my R distribution ...
3
votes
2answers
91 views

How to define a nestable Baseform function, BaseForm output becomes BaseForm input

Mathematica won't change a number's BaseForm recursively: 63969 // BaseForm[#, 16] & // BaseForm[#, 8] & // BaseForm[#, 2] & Well, I inspected former ...
1
vote
0answers
90 views

V10 interface problems

Has anyone noticed the following? Sometimes when I bring up the Help->Wolfram Documentation there is no text field to type into. When I bring up Find and Replace there are two text fields for Find: ...
5
votes
2answers
149 views

Example of Integrate applying a numerical evaluation N

Here is a minimal example: Integrate[(a[1] + x)^2, {x, 1., 2.}] 2.33333 + 3. a[1.] + 1. a[1.]^2 The problem is that ...
2
votes
0answers
111 views

How do I write “such that” in mathematica? [closed]

I have a mathematical statement as follows : Tri := {(t1,t2): t1,t2>=0,t1+t2<=1} How can I tell Mathematica that I need to define vectors (t1,t2) 'such ...
6
votes
3answers
211 views

Laplace: from differential equation to transfer function

First at all, this is trictly related to my own question: How to transform transfer functions into differential equations? How can I transfer my differential equation into a transfer function? For ...
1
vote
1answer
148 views

Strange behavior of function (memory leaks)

I have some funtion: ...
7
votes
4answers
527 views

Solving $L=\frac{3}{2} \sqrt{4 \pi ^2 A^2+W^2}-\frac{\sqrt{5 W \sqrt{4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt{2}}+\frac{3 W}{2}$ for $W$

When I solve the aforementioned equation for $W$ or $A$ on Mathematica I get a long and ugly equation in return, namely one of the solutions for $W$ is: (attempt to read at your own health) ...
16
votes
6answers
875 views

How to understand the usage of Inner and Outer figuratively?

Description: In Mathematica the functions like Thread, Inner, Outer etc. are very important ...
3
votes
2answers
275 views

Integral converging in M9 but not in M10

Background: Mac OSX 10.9.4, Mathematica 9.0.1 vs. Mathematica 10.0 (both versions are Student Editions). I have a notebook. It used to evaluate fine in Mathematica 9. I upgraded to 10 and, without ...
2
votes
2answers
155 views

How to get the current index during a Scan iteration?

Is there a special keyword to get the current index in Scan ? For example, let say I have the following code : ...
0
votes
2answers
199 views

Find Root Iteration

I have an iterative sum from $k=0$ to $k=n$ where the resulting sum is a polynomial of degree $n$. I want to find the numerical root of this polynomial using FindRoot, starting from $x_0$ where the ...
4
votes
3answers
156 views

Split matrix by all-zero columns

Below is my input: mat = {{0, 0, 0, 0, 0, 1}, {1, 0, 0, 1, 0, 1}, {0, 1, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 1}, {1, 1, 0, 1, 0, 0}, {0, 0, 0, 1, 0, 1}}; ...
3
votes
1answer
111 views

Wavelet expansion of given function (as opposed to DWT of given data)

To illustrate, say I take the following function (the reason for the square root will be apparent soon) ...
2
votes
0answers
97 views

Result of symbolic integration changed drastically by making assumptions

I would like to know the underlying reason for different outcomes for the two integration operation below. One of them includes a few assumptions, otherwise both have the same integrand: ...
7
votes
2answers
181 views

Account for powers of 0 and 1 when defining function

I have a function that I am defining as (assume m,n,a,b are non-negative integers): myfcn[x_^m_ p_^n_, x_^a_ p_^b_] := basefcn[m, n, a, b]; and then extending to ...
3
votes
5answers
169 views

Algebraic expressions on pure functions

I would like to know how to perform algebraic operations with pure functions. Simple version: Here's a silly toy model: I want to transform the algebraic expression Sin*Cos into the function ...
7
votes
1answer
153 views

How do I speed up a plotting of NIntegrate when repeated multiple times inside Plot?

I am studying a set of functions (many of which I know only as a definite integral) and I have assembled into a list. Here is a sample: ...
4
votes
2answers
213 views

Density plot of city data

I try to solve a bit tricky problem. I want define line (or vector) between some geographical points with weights (for example how many transactions has been done between these cities). I tried this ...
26
votes
1answer
644 views

Proving the hairy ball theorem using xAct

I would like to formally prove the hairy ball theorem in Mathematica, initially just for $S^2$, and then see about generalizing. An approach I thought about to use the xAct package to define $S^2$ ...
6
votes
2answers
260 views

Converting a string into a nested list of strings

The following string can be converted easily into a list with ToExpression ...
8
votes
1answer
135 views

How to sort the functions in a Package?

Once a Package like abc` has been installed, we can use "?abc`*" to scan all the functions defined in this Package. Now I ...
5
votes
1answer
78 views
3
votes
0answers
121 views

Implementation of the Vector Autoregressive Model

I need to code/write a Vector Autoregressive Model VAR(p) as a function of the parameters. There is no estimation, nor Data involved, this is a "population" exercise: Assume X and Y are univariate, ...
13
votes
2answers
294 views

Export Plots to PNG in Printout Style

When creating a plot in Mathematica 10 (OS X 10.9.4 and Win 7) the FrameLabel and Ticks are greyish and only the Frame itself is black (see Screenshot bellow). Only when exporting the plot to PDF all ...
13
votes
0answers
100 views

Hyperlinks not preserved when saving in PDF format in MMA V10

I usually create my course contracts in Mathematica and then save them in PDF format. The notebooks include hyperlinks and these have transferred to PDF without problem over the last several versions ...
0
votes
0answers
34 views

Retrieve style definitions [duplicate]

How can I retrieve the style definitions of a certain style within a cell, notebook or stylesheet? For example how can I retrieve the FontColor and ...
7
votes
2answers
429 views

Mapping data on Archimedes' spiral

I would like to map my data on Archimedes' spiral and preserve the distance between points on the curve. The test data consists of 20 evenly spaced {x,y} ...
2
votes
1answer
45 views

Imaginary term in Integration procedure

How do you remove the imaginary term in the integrated output? Compare the outcome from the operations below. The first operation yields an imaginary term, while the second one has none. ...
8
votes
1answer
107 views

Possible Bug in ProbitModelFit when used in a Dataset

Since upgrading to Mathematica 10 on Mac OSX I have come across a number of instances of this error, which occurs using Probit and Logit model fit. A bit of googling show this is something to do ...
4
votes
1answer
132 views

Boundaries of graphical objects not displayed correctly

I have encountered two situations where Mathematica 10 is mishandling the outer pixels of plainly simple objects. I input this: ...
4
votes
2answers
245 views

Coordinate extraction and manipulating graphs as graphics objects

Consider the image below: GraphData[{"Wheel", 7}] Is it possible in Mathematica to lay several of these Graph along each ...
4
votes
4answers
116 views

Plot range of a 2-dimensional function as a function depending on one variable

I want to plot a function of 2 variables x and y, for discrete values of y, like: ...
5
votes
1answer
45 views

Package function not called from button in a DockedCell expression

Consider the following minimal example package: ...
1
vote
1answer
56 views

Importing additional custom data in DIMACS format

I have graphs in DIMACS format, with vertex colors specified. The vertex colors are denoted by lines n u c, where u is the ...

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