0
votes
0answers
1 views

How to solve for exponents in an infinite product?

Say I have a power series, $f(x,y) \in 1 + x\mathbb{Z}[[x,y]]$ Then it admits a unique expansion $$f(x,y) = \prod_{i=1}^\infty \prod_{j=0}^\infty (1 - x^i y^j)^{n_{i,j}}$$ for some integers, $i, ...
0
votes
0answers
5 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. ...
9
votes
4answers
142 views

Make MapIndexed listable

My goal is to apply MapIndexed to every element of a nested list without destroying the arithmetic operations within the elements. For example, let's start with ...
3
votes
3answers
144 views

DSolve not finding solution I expected

Try to solve the following ODE via DSolve $$ \left\{\begin{aligned} y'(x)+2 y(x) e^x-y(x)^2 &= e^{2 x}+e^x \\ y'(0) &=1 \end{aligned}\right. $$ The ...
0
votes
0answers
19 views

Two problems with NDSolve when using Method -> Projection

I tried to solve a system first order differential equations together with a constraint equation. I use the Method -> Projection to check if the constraint holds ...
0
votes
0answers
31 views

Horizontally compress a picture with varying compression ratio

I have a function c[x] whose domain and range are both [0,1]. And I have a picture with width W, height ...
0
votes
2answers
223 views

Integrating polynomial functions over polytopes with an add-on package

There is a Mathematica package to evaluate integrals over polytopes: http://library.wolfram.com/infocenter/Books/3652/ In the documentation (Functions.nb file) I ...
7
votes
1answer
55 views

On using DiracDelta[t] in OutputResposne in version 10. Different result from version 9

I am baffled by this. I was trying to run same example I had working in version 9.01 and found now I get empty plots. The example is here . Here is a simplified version of the above. The same exact ...
3
votes
3answers
96 views

How to count the integer grid numbers defined by inequalities?

I have the following code to show a red area defined by inequalities: ...
1
vote
2answers
169 views

Integral converging in M9 but not in M10 [on hold]

Should I assume that nobody else mamaged to reproduce this behaviour ? Background: Mac OSX 10.9.4, Mathematica 9.0.1 vs. Mathematica 10.0 (both versions are Student Editions). I have a notebook. It ...
3
votes
0answers
11 views

How to export .mtl files for 3D textured objects

I would really like to deploy my textured 3D graphics in the web with sketchfab in my blog. Unfortunately, Mathematica only exports the shape of the 3d graphics, i.e. the .obj file, but omits the ...
2
votes
2answers
220 views

Need help evaluating definite integral to a function of Y

Suppose $Y = \sqrt{2T}\cos(U)$, $ 0 \le u \le \pi $, and $ 0 \le \cos^{-1}(\frac{y}{\sqrt {2t}}) \le \pi ) $, so $ -1 \le \frac{y}{\sqrt{2t}} \le 1 $, with all $ \mathbb{R}$. The iterated integral ...
1
vote
1answer
33 views

Connect to Windows kernel from Linux computer

I've seen many questions regarding the connection to a Linux machine from a Windows one, but I need to do the opposite. Situation: I have Mathematica on my Linux laptop (...
0
votes
0answers
23 views

Window ▶ Show Handwriting Input

How might I force Mathematica to display the Handwriting Input menu? Currently I'm on W7 using a Wacom Tablet and unable to find the Handwriting Input option.
10
votes
1answer
333 views

Map of Specific US States? (Isolated)

My question here is fairly basic, and I'm sure I'm overlooking something basic. I know about CountryData for creating shapes of entire countries, and it works, to ...
3
votes
3answers
112 views

How to test if all the elements in a list are Integers? [closed]

Consider a list such as s={1,2,3,3,5,6,3} With IntegerQ[number] , you know if number is an ...
7
votes
2answers
152 views

Slow work of SQLInsert with SQLite

I want to store my data in SQLite database, but writing large numbers of data its too slow. For example: ...
6
votes
4answers
727 views

Can't compute definite integral

Consider a scalar field (in polar co-ordinates), $f(r) = l-r$. Now I want to evaluate the field integral over a circular region of radius $b$, centered at a distance of $x$ from the origin. According ...
5
votes
2answers
208 views

Using NSolve in the complex plane

I am trying to find numerical values for $\Im\ e^{\frac{1}{2} +i\ y} = \Im\ \zeta(\frac{1}{2} +i\ y)$ for a given range. I have tried: ...
1
vote
1answer
54 views

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

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: ...
3
votes
2answers
75 views

Expectation of a composite Markov-Gamma distribution

In a model I have a discrete two-state first order Markov process, defined by a (2x2) transition matrix with two free parameters. If the first state occurs then the process outputs zero for that ...
2
votes
3answers
191 views

How can I get the function of a plotted trajectory? [on hold]

I solved two ODEs, which are a function of t, numerically. The first ODE is the vertical equation of motion and the second one is the horizontal equation of that ...
2
votes
1answer
87 views
-4
votes
0answers
28 views

Visualization of tangent plane [on hold]

Please send me comple source code of http://demonstrations.wolfram.com/TangentPlanesOnA3DGraph/
0
votes
0answers
31 views

Lightweight Grid preferences screen stopped working after v10 install

I am getting the following error when I try to open the Lightweight Grid "Preferences" tab... ...
9
votes
3answers
913 views

Replace expressions with symbols

First of all: I'm new to Mathematica, so I would appreciate it if the answers are quite complete. I have the result of calculation that is expressed in $\sin$ and $\cos$. Now, all of these can be ...
8
votes
2answers
77 views

Automatically add appropriate prefix to Quantity

Is there a function that automatically adds the appropriate prefix to a Quantity object? For example, I would like a function ...
11
votes
1answer
93 views

Is it possible to insert new colour schemes into ColorData?

Because of the standards in my field, for many plots I need to use (or at least end up using) rather narrowly defined colour schemes, and in particular the Matlab "Jet" scheme, which is well described ...
2
votes
1answer
84 views

May I restrict caching to disk when memory runs low? [duplicate]

An hour ago, I had to hard reset my laptop again because Mathematica froze the system again. When import a large file or make a mistake that produces huge arrays with complicated entries etc., I often ...
0
votes
1answer
63 views

How to apply a trigonometric identity to a formula

The product of cosines is given by (Wikipedia): $ \prod_{k=1}^{n} \cos{\theta_k} = \frac{1}{2^n}\sum_{e\in S} \cos(e_1\theta_1+\ldots+e_n\theta_n) $ where $S={1,-1}^n$. How can I apply this to a ...
0
votes
2answers
47 views

How to use the output we see of expression when this expression is inside Dynamic

Consider this example: Manipulate[status = Dynamic[If[a < b, Yes, No]], {a, 2}, {b, 5}] The output of this calculation is ...
1
vote
2answers
597 views

Computing 10-dimensional volume of a 9-sphere

I'm trying to compute 10-dimensional volume of a 9-sphere with radius r using Monte Carlo. ...
13
votes
0answers
226 views
+50

Proving the hairy ball theorem using xAct

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

FullSimplify giving unexpected result

When I perform a FullSimplify on the list $$ \left\{-\sqrt{5-2 \sqrt{6}},\sqrt{5-2 \sqrt{6}},-\sqrt{5+2 \sqrt{6}},\sqrt{5+2 \sqrt{6}}\right\} $$ I get $$ ...
8
votes
1answer
145 views

Map of United States as a 3D histogram

By combining the state data from here and the extrusion code from here I have managed to make prisms of the various US states such as However, the extrusion method looses information about the ...
7
votes
3answers
133 views

Different results with DateRange and LeapYearsQ in Mathematica 9 and 10

With Mathematica 9.0 for Mac OS X x86 (64-bit) (January 24, 2013) one could use DateRange[{2000}, {2010}, "Year"] to achive ...
6
votes
2answers
203 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 ...
2
votes
2answers
98 views

Interacting with 3D Graphics, for export [closed]

Are there any export formats which preserve the ability to interact with 3D Graphics? (In particular, the ability to rotate.) EDIT: I've found this question: How to make a 3D plot auto-rotate? ...
29
votes
1answer
524 views

Incompatible Changes since Mathematica Version 7?

There is documentation of the incompatible changes made to Mathematica with each major release: Incompatible Changes since Mathematica Version 1 Unfortunately that documentation simply stopped ...
4
votes
1answer
94 views

How to vary line thickness to add a sense of perspective?

Is there a simple way to vary the line thickness relative to the viewpoint so as to add a sense of perspective? Take for example the following: ...
12
votes
1answer
140 views

Export dataset to JSON

I'm experiencing a weird issue. Consider a dataset defined like this: dataset = Dataset[{<|"a" -> 1, "b" -> 2|>, <|"a" -> 3, "b" -> 4|>}]; ...
12
votes
1answer
314 views

What is the real default CellEvaluationFunction?

The default CellEvaluationFunction is Identity but one can quickly see that this is handled specially as an equivalent function, ...
0
votes
0answers
42 views

Disable Input Assistant Mathematica 10 [duplicate]

In the new Mathematica 10, every time I hover over a function for more than 0.001 second, this stupid box appears. In Mathematica 9, I had disabled it. However, no matter what I change in the ...
0
votes
0answers
43 views

Calculate the power spectral density of a Markov chain

I would like to calculate the symbolic power spectral density of a two state Markov process with a symbolic transition matrix characterised by two parameters. I have tried the below, but it doesn't ...
0
votes
0answers
30 views

NDSolve::derarg error: requiring pure function in solving differential equations

I'm trying to numerically solve 2 partial differential equations eq1 and eq2 given the boundary conditions in ...
0
votes
2answers
114 views

Poincaré Section

I have encountered somewhat the same problem as here. But with the equations, $x'(t) = p(t), p'(t) = - x(t) - y(t), y'(t) = q(t), q'(t) = - y(t) - x(t)$ My code is, ...
32
votes
7answers
4k views

How do you convert a string containing a number in C scientific notation to a Mathematica number?

Suppose I have a string containing the C-representation of a floating point number, for example s = "1.23e-5" and I want to convert this to a Mathematica number. ...
2
votes
2answers
112 views

The i-th element of a permutation [duplicate]

I am trying to run something of the form ...
0
votes
1answer
52 views

Control which frontend session/kernel the Workbench gets attached to

(I am new to Workbench) I have 2 or 3 Mathematica frontend sessions open with a few of them running some long-running codes. When I try to open/edit a code in Workbench, I see that it sometimes it ...
1
vote
0answers
62 views

Is it possible to add page break in front-end? [on hold]

Description: I have accomplished my undergraduate paper as a Mathematica notebook. In this condition, I find it convenient to typeset formula and words in a notebook environment. However, I feel ...

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