0
votes
0answers
27 views

how can I manage the characters encoding of retun value from FetchURLWithHeaders?

I have retrieved a file from a web server by means of the FetchURLWithHeaders function. The retun value from FetchURLWithHeaders should contains the substring SCHØNHEYDER but instead I find ...
0
votes
1answer
34 views

How to query W|A, to get a list of asymmetric, bicubic and $3$-edge colorable graphs? [on hold]

I'm interested in finding graphs with certain properties, like the smallest cubic bipartite asymmetric graph. While working on a related graph-theoretic problem, concerning edge-colrings, I came along ...
9
votes
1answer
144 views

Why can AppendTo modify a referenced list in-place but Part cannot?

Part, AppendTo, PrependTo, AddTo, etc. allow in-place modification of a list, but only Part requires that the list be referenced through a simple symbol, e.g. the following all does what you'ld ...
2
votes
1answer
79 views

How to obtain numerical answer for equation containing integration

Could some one tell me how to obtain numerical value of $a$ and $b$ from equations below: $$\frac{1+exp(b)}{1+exp(0.9a+b)}=0.95$$ $$\int_{0}^{\infty} \frac{1+exp(b)}{1+exp(a x+b)}=1$$
0
votes
0answers
18 views

Why are many answers posted as comments? [migrated]

I have noted that many questions appear to have 0 answers, when there are several answers given as comments. What is the exact protocol for when an answer should be posted as an answer (or not)?
1
vote
1answer
71 views

Mean Preserving PDF Spreading

I have a histogram representing the PDF (probability density function) of an unknown discrete RV. The histogram is asymmetrical. Is there a known way in Mathematica to increase/decrease the variance ...
0
votes
0answers
30 views

Testing for a vector of all reals [duplicate]

I want to test if an expression is a vector of all reals. I defined RealVector[expr_]:=VectorQ[expr,NumberQ[#]&&(Head[#]===Real)]; Trying this on ...
0
votes
0answers
21 views

Keep Only Csv Files! [on hold]

I have the following string list: listAll={fichie1.csv,fichier2.csv,fichier3.pdf,fichier4.exe} is there a fast way to keep only the csv files without doing a loop? my goal is to get the following ...
6
votes
3answers
220 views

Finding all sublists or substrings of a given list/string

Given a list or string, how do I get a list of all (contiguous) sublists/substrings? The order is not important. Example for lists: ...
0
votes
2answers
28 views

Retrieve Options from function other than graphics objects

We can retrieve information about used Options for Graphics via: Options[Plot[Sin[x], {x, 0, 1}], "AspectRatio"] (* {AspectRatio -> 1/GoldenRatio} *) even if ...
1
vote
2answers
70 views

calculate missing values, Interpolation

I've following data: ...
2
votes
3answers
107 views

How to make $a1**a2** \cdots **an=0$ for a given $n$?

In order to optimize my computation and save memory, I'd like to modify NonCommutativeMultiply so that for a given $n$ one has $a1**a2** \cdots **an=0$ for any $a1, a2, \ldots, an$. To make it ...
7
votes
3answers
150 views

Localising OptionValues

The documentation on OptionsPattern leaves me with some unanswered questions. From the example section: ...
1
vote
1answer
69 views

How to properly apply NumericQ or s.th. similar here? - NDSolve inside NMaximize

I wrote a function that numerically solves a given Schrodinger equation and returns replacement rules to obtain the time evolution operator. It looks and is used as follows: ...
0
votes
1answer
45 views

How to put a fixed sized frame around traditional form expression

The height of a 2D form of a polynomial changes depending on the existence of exponents, fractional coefficients, etc. For use inside a Manipulate, I would like to ...
3
votes
2answers
198 views

Equivalent of Matlab's uigetfile in Mathematica

I was wondering if there an equivalent of the "uigetfile" Matlab function to use it in Mathematica. To be more precise, I want to read many Excel files and I don't want to type a static path; ...
2
votes
3answers
88 views

Testing for a vector of reals [on hold]

Suppose I define: RealVector[expr_]:=VectorQ[expr,NumberQ[#]&&Head[#]===Real)]; Then: ...
1
vote
1answer
64 views

User Input Through Dynamic

For my application, I am using Dynamic functionality to make a number of input fields through which a user can enter numbers. I then take these numbers and place them as the entries in a dynamic ...
2
votes
4answers
124 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
1answer
71 views

Finding x when sin(x) = -.758 [on hold]

I'm not understanding how to find all the angles for when sin(x) is equated to a negative decimal can someone explain to me how to find it..? So far I came up with 49.288 degrees, and 229.288 degree. ...
1
vote
2answers
124 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 ...
3
votes
3answers
311 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
48 views

How to sample only odd numbers in the domain of a table for list plot [on hold]

The following code samples $k$ points around a circle at integer values starting from $0$: ListPlot[Table[{2 Sin[(2*y/x)*π*n] , 2 Cos[(2*y/x)*π*n}], {n, 0, k}] I ...
0
votes
0answers
46 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 ...
10
votes
0answers
85 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
36 views

Sum of derivatives [closed]

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: ...
0
votes
0answers
45 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 ...
0
votes
0answers
27 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 ...
10
votes
0answers
84 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 ...
2
votes
1answer
45 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 ...
5
votes
1answer
151 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 ...
-1
votes
0answers
46 views

What is a Horn Clause? [closed]

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 ...
0
votes
1answer
35 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 ...
1
vote
1answer
65 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 ...
1
vote
1answer
46 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 ...
0
votes
0answers
24 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 ...
4
votes
1answer
46 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: ...
2
votes
0answers
48 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 ...
1
vote
1answer
50 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: ...
3
votes
2answers
277 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 ...
0
votes
0answers
20 views

Maintain a function quality of an expression [on hold]

I have written a simple code in Mathematica to put a matrix into a vector. The matrix was a function of a variable n, and I want the new vector to also have this quality as a function of n. ...
3
votes
0answers
77 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 ...
2
votes
1answer
84 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 ...
2
votes
1answer
91 views

How to filter a dataset using Select and a parameter

I'd like to filter a Dataset using a parameter in Select, but so far I haven't been able to make it work properly. Say that I ...
0
votes
0answers
54 views
0
votes
0answers
38 views

Brevity of denoting Conjugate[]

How do I make Conjugate[] expressions have a bar above them instead of Conjugate[ before them, in order to shorted up expressions? I'm looking at something like this screenshot for example:
1
vote
1answer
139 views

Understanding SameQ

I am new to Mathematica. So I have read the documentation for comparing expressions in Mathematica and I still don't get the SameQ (===) function. Let me give you a short example: ...
5
votes
4answers
285 views

Long list of similar rules

Given the following: ...
0
votes
0answers
31 views

How to join datasets? [closed]

I have 3 datasets as a lsit: {dataset1,dataset2,dataset3} I want to convert them into a single dataset. The following does not work Join[{dataset1,dataset2,dataset3}] However, this works ...

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