0
votes
0answers
44 views
2
votes
4answers
115 views

accessing elements of nested list

I have a list of the form: toy = {{a, {b, c}}, {d, {e, f}}, {g, {h, j}}, {k, {m, n}}}; and would like to create the list ...
0
votes
0answers
20 views

How to explain the correlation between the mean of each element and it's corresponding PC1 coefficient in a data.frame? [on hold]

I am doing some PCA analysis by R now,I have a data,which is a data.frame:a,ncol(a) =1000,nrow(a)=100,each row represent a sample,each col represent a feature,so when I use R do PCA analysis like ...
6
votes
2answers
694 views

How do I display imported images at actual size?

I know that this is an extremely basic question, but I am having a lot of trouble finding the answer in the documentation. When I import an image (for example, ...
1
vote
2answers
119 views

Inconsistent image sizing with Grid and Row?

Can anyone explain why Row and Grid don't size the image correctly and consistently to 300 ...
0
votes
1answer
30 views

Series expansion of large expression

I have the following equation: eq=E0[x,y,z]+E1[x,y,z]*Cos[phi]+E2[x,y,z]*Cos[phi]^2+E3[x,y,z]*Sin[phi] Now E0,E1,E2 and ...
43
votes
1answer
754 views

Is this 30% slowdown in Mathematica 10 due to DownValues lookup time?

Running several numerical self-programmed packages I realized already some time ago that Mathematica 10 needed between 20 and 40% more time. I did already report this of course with a simple example ...
1
vote
1answer
49 views

Getting a part of a matrix Inverse for later use

I was trying to get an element of a matrix, and use in further computation of my program. Problem was that its not reading the value unless and until I specify it again. My code is: ...
2
votes
3answers
241 views

How to create a Disk with smoothly changing coloring?

I want to have a disk. But this disk shouldn't have a fixed color; instead, I'd like it's color to fade smoothly. Until now, I came up with two ideas how to achieve this. Idea #1: ...
0
votes
1answer
129 views

How to export figures with normal spacing in texts?

My OS is Ubuntu 14.04, and I use MMA 10. I export a figure ploted in MMA to a pdf file and then import the pdf in Latex, here is the sreenshot As you can see, the spacing in the text is odd. But ...
1
vote
2answers
56 views

Insert an element to AdjacencyGraph

I'm not able to insert an element to mine AdjacencyGraph. I suppose that i should modify my AdjcencyMatrix: ...
5
votes
4answers
258 views
10
votes
0answers
76 views

Incorrect use of Scaled causes crash

Bug introduced in 8.0 and persisting through 10.0.2 or later While playing with Scaled, I made a syntax error which caused a crash instead of an error message ...
0
votes
0answers
44 views

How to Fold (FoldList) this in a more compact (efficient) way?

Example code: x = Table[something[i], {i, 5}] Table[Fold[f1[#1, f2[#2, a], a] &, x[[i]], {c1, c2, c3}], {i, Length[x]}] This above is just an example. I ...
5
votes
1answer
53 views

Why does Mathematica remember print settings?

Mathematica has a strange behavior with respect to printing and saving to PDF. It remembers the print settings, such as page range and number of copies along with the file. So if I print 50 copies ...
36
votes
3answers
2k views

Mollweide maps in Mathematica

Context In my field of research, many people use the following package: healpix (for Hierarchical Equal Area isoLatitude Pixelization) which has been ported to a few different languages (F90, C,C++, ...
10
votes
0answers
71 views

Reading from a socket stream

I noticed an undocumented socket package (SocketLink) in Mathematica (Using version 10, not sure when it was actually added) and wrote a barebones HTTP responder ...
4
votes
1answer
129 views

Largest matrix size supported by Mathematica 10

I have need to store large square matrices in memory, some times sparse, some times not. I have used up to $2^{15}$ by $2^{15}$ as my upper bound so far, and Mathematica has handled it even if it took ...
0
votes
0answers
35 views

Sum of derivatives [on hold]

I'm trying to write the expression: $$\sum_{i=1}^3 g_{ii} \partial_i \partial_i f,$$ where $f$ is a function of variables $\{x_1, x_2, x_3\}$ and $g$ is a 3x3 matrix. My expression is: ...
15
votes
4answers
3k views

Getting the interpolation function from a list plot

I have conducted a chemistry experiment and obtained a list of concentrations of a reactant against time. I plot a graph of this using Mathematica's ListPlot ...
0
votes
0answers
42 views

Applying the square root of operator on polynomial functions

I am trying to apply an "operation" on polynomial functions: apply the operator $(\frac{\partial f}{\partial x}-y\frac{\partial f}{\partial z})^2+(\frac{\partial f}{\partial y}+x\frac{\partial ...
41
votes
10answers
4k views

Having used Mathematica as a “gateway” language, where to from here?

I have been using Mathematica for about a year. It is the first language that I have attempted to learn. I'm still very much a newbie, but there are moments I feel more like I am waving than drowning. ...
1
vote
1answer
102 views

Why does Mathematica add Hold to the result of my user defined symbol?

In the code below I have defined a symbol that multiplies two block-matrices (I can't use the builtin Dot since Dot assumes that the matrix coefficients commute): ...
2
votes
1answer
42 views

How to access directly the “CUDA Memory” address from another parallel kernel?

I work with CUDALink and have some small successes. I use direct calculation on GPU without using CPU (only for sanding commands for CUDA function). Until now I have stored on the hard drive with ...
0
votes
0answers
31 views

Plotting result of symbolic equation [on hold]

I used Solve to obtain a one parameter set of three solutions for a complex-valued cubic equation. How do I plot the resultant solutions? ...
0
votes
0answers
24 views

What kind of objects in NETLink for PicoScope interfacing?

I have two issues in my mathematica code for control PicoScope using NETLink. PicoScope series 3206 remote controll was in one paper already shown ...
4
votes
1answer
86 views

Definitions are not distributed to parallel kernels

I have a small package with utilities, which looks like that: ...
0
votes
1answer
444 views

Solve non linear system of equations

I am trying to solve a system of two equations with two unknowns. In these equations I have, a part from constants: Unknown nr 1, $$D_{\perp}$$ Unknown nr 2, $$\omega_C$$ Known function of r: ...
6
votes
1answer
108 views

How to track Part of Symbol or How to symbolize Parts of Symbol without copying data

Let's create simple function: SetAttributes[h, HoldFirst]; h[data_] := Dynamic[Grid[data], TrackedSymbols :> {data}] test = RandomReal[1, {2, 2}]; h[test] ...
14
votes
2answers
1k views

Some tutorials on formatting notebook for exporting to pdf

I love the way that Mathematica allows me to type in of formulas. It is really easy to type complicated expressions with shortcuts on the keyboard. It would be great if I could use Mathematica ...
1
vote
1answer
62 views

How to use a list of rules as a data set

I have a file of models that I have saved that I want to be able to call in another program to be solved with NDSolve. Can I use ...
0
votes
0answers
23 views

Getting a remote kernel from a machine not directly reachable

I have a machine capable of running Mathematica on 24 cores which I would like to take advantage of :) The only problem is that this is a remote machine to which I cannot connect directly, I have to ...
-1
votes
0answers
44 views

What is a Horn Clause? [on hold]

I am not an expert in Mathematics :) thus if someone can let me know What is a Horn Clause in layman's terms? I know it is used in First order Logic but I am unable to understand what is it and how to ...
3
votes
0answers
69 views

Mathematica GUIKit

Does anyone of you know if the GUIKit package is still under some development by Wolfram Research or is the current version 1.1.0 the last one. Does it make sense to make GUIs using this package in ...
1
vote
1answer
43 views

Defining a matrix with the symmetry Transpose[A(q)]=A(-q)

I am trying to construct a symbolic matrix with the following property- $$ \left(D_{3\times3}(q)\right)^T = D_{3\times3}(-q) $$ Note that for $q\in \mathbb{R}$, $D(q)$ would be hermitian. So far i ...
4
votes
1answer
43 views

TensorReduce not simplifying transpose for symmetric matrix?

I know Mathematica is not very good with symbolic manipulation of matrix expressions, but I was surprised to find that it can't reduce the following expression: ...
7
votes
0answers
125 views

$3\times 3 = 6 + \bar{3}$ in Mathematica?

Can Mathematica handle this type of algebra, which is used very frequently in e.g. particle/nuclear physics? That is, I want to decompose a product of representations (in $SU(N)$ say) into irreducible ...
0
votes
0answers
78 views

How to render a 3d image of the galaxy? [on hold]

I recently came across the Uniview software package, there has even been a TED talk about it. Here is another example of some interactive views of star maps. In Mathematica 10 AstronomicalData has ...
-1
votes
1answer
62 views

Append plot to existing plot?

I have generated a plot from t=0->1, and I wish to append another plot from t=1->2. How can I do this? Thanks in advance.
2
votes
0answers
38 views

NDSolve is running an extremely long time: how can I save the existing data?

I am trying to solve a PDE by the following code. It takes 1 hour or so to reach t=25.72 but about 20 hours to reach t=25.72404031638060174049337306126853310997. Actually, the time step is extremely ...
0
votes
1answer
59 views

ParallelTable and global variables

I want to calculate the convolution of two function. In order to generate variables automatically, I use such an expressions: ...
3
votes
2answers
268 views

How do I show only the intrinsic color of 3D polygons?

System: Mathematica 9, Windows 7. I want to assign a polygon a color in such a way that it is rendered in that color irrespective of any ambient light sources. In other words I want Yellow to be ...
8
votes
2answers
691 views

OpenSCAD like functionality with Mathematica?

I keep seeing reference to use of Mathematica as a CAD tool (for instance: http://www.makerbot.com/support/guides/design/). I'd like to use it as such if feasible, but I'm having trouble locating ...
1
vote
1answer
52 views

Finding the true expectation

I have the density function and I want to determine its expected value ...
1
vote
0answers
82 views

Creating Scheduler

I am trying to build a scheduler program like pizza delivery. Each driver will choose their time and general working schedule will be updated similarly. Problem is number of workers change. How can ...
1
vote
0answers
58 views

I need some GPU benchmark for Mathematica

I am considering to buy a GPU. I need to know two things: Is it possible to solve a system of differential equations using GPU and Mathematica's functions? I need to know how much faster would be ...
1
vote
0answers
45 views

Updating a GUI with ComboBox using GUIKit

Dear Mathematica users, does anyone know how I can update my existing Gui window (made with GUIKit) by choosing different values of a ComboBox so that different and multiple TextFields etc appear ...
0
votes
2answers
144 views

Exctrating data information from a file.txt

I really did previous long search in the site and I couldn't find any answer that might help me. So I am asking it. I have the following data set, ...
1
vote
0answers
52 views

How to make hollow Graphics3D?

I keep seeing a notebook to use of Mathematica as a 3D Printing tool (e.g.: this link). In the notebook on slide 8/11, we find these pictures: I'd like to design it as such that, but I don't ...

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