2
votes
1answer
149 views

Manipulations with options

I have two functions with options, for example f and g ...
2
votes
1answer
85 views

How do I find the analytical roots of this polynomial? [closed]

I want to find the analytical roots of this polynomial - x - a^3*x*(a^2*x*(a*x*(x - 1) + 1)*(x - 1) + 1)*(a*x*(x - 1) + 1)*(x - 1) ...
1
vote
1answer
54 views

Cross product of three vectors

I am following the answer of Jens from following post: How do I simplify a vector expression? vec /: Cross[vec[x_], HoldPattern[Cross[y__]]] := I want to create ...
1
vote
0answers
44 views

x and y axis nonlinear error fit possible? [duplicate]

I have a set of datapoints with x (position) errors as well as y (measurement) errors. Is there a way in Mathematica to fit a nonlinear function through this points, with weighting both, the x and y ...
3
votes
1answer
96 views

Plotting a finite series w.r.t. a parameter [closed]

So I would like to plot the series below: $$ S_q = k \frac{1-\sum_{i=1}^{W}(1/W)^q}{1-q} $$ where $k$ is a constant which I assume for now to be equal to 1 and $q \in \mathbb{R}$. However, for my ...
2
votes
1answer
107 views

Problem with Volume [closed]

A bug probably. This should give the volume of the unit sphere: vol = Volume[{1. r, th, ph}, {r, 0, 1}, {th, 0, Pi}, {ph, -Pi, Pi}, "Spherical"] but it gives: ...
12
votes
1answer
134 views

How to count the number of the tube

There is a picture Get the binary image binimg = ColorSeparate[img][[2]] // Binarize[#, 0.25] & // Thinning Visulize the result of regconization ...
4
votes
0answers
127 views

Finding eigenvalues in Mathematica: why so slow?

I am trying to find the eigensystem of a large sparse real symmetric matrix, and I only need the lowest 40 or so eigenstates. The relevant code is as follows: ...
3
votes
2answers
118 views

How to integrate on bezier function?

I have: points = {{0, 100}, {250, 0}, {0, 300}, {500, 500}} And I want to know the area below the curve, so I came to: ...
0
votes
0answers
49 views

frequent slow evaluations for trivial expressions, large memory loaded

After loading a lot of data into memory and evaluating several hundred expressions without any problems, trivial expressions such as (1+2) take about 5-10 seconds to evaluate. Sometimes they are ...
1
vote
1answer
40 views

How to correctly use FormulaData

I am exploring some of the functions involving units and formulas, and wondered how to input quantities if the variable has a subscript. This works ...
3
votes
1answer
55 views

Angle between two vectors in spherical coordinates [closed]

I have two vectors: H = {1, 0, π/4}; EA = {1, 0, 0}; Which I want to be in {r, Phi, Theta} - which would should give an angle between the two vectors as ...
1
vote
0answers
30 views

How to import/export to libsvm?

Under the hood Mathematica uses libsvm, so I don't think this question is beyond the pale. I need to export an svm I trained with Classify to the standard SVM Format (which is readable by libsvm). ...
1
vote
2answers
129 views

How to find adjacent polygons of a specific polygon in a VoronoiMesh?

I have developed a code for VoronoiMesh. I am also able to find the polygon with highest number of adjacent polygons. How do I find the indices of the adjacent ...
1
vote
1answer
41 views

Get Isotope Data and Electron Mass in Same Units - kg and Kilograms

I'm trying to find the nuclear mass of $^{238}\text{U}$. To do this, I subtract the electron mass from the atomic mass. I'd like to find the final answer in kilograms. I'd also like to use ...
4
votes
1answer
72 views

Grayscale Morphology

How can I achieve grayscale morphological operations on 2D images in Mathematica. With morphology I mean operations like Dilation and Erosion. With grayscale I mean the operations that take images and ...
4
votes
2answers
86 views

How can I make this code to count Hamiltonian paths faster?

I have this very basic code to count Hamiltonian paths in a graph: ...
2
votes
1answer
91 views

working hours and negative time [closed]

I have a list of TimeObjects. I want to subtract 5h from each element and if TimeObject < 5h then give a negative hour. My ...
6
votes
1answer
103 views

Using two rules for the same variable

I am a newbie in the field so please not angry. I am reading the tutorial below and having a problem. Link: How to Create and Use Rules From the link: If you give two rules for the same ...
10
votes
1answer
70 views

Arrows from GraphicsComplex not converted to Normal form correctly

Bug introduced in 7.0 or earlier and persisting through 10.3.1 or later Show @ Graph[{1 -> 2, 2 -> 3}, Frame -> True] Normal @ % Is this a pure bug, ...
3
votes
2answers
49 views

Thickness of bars in a histogram

How can I control the thickness of the bars (here vertical lines) in a Histogram plot? For example in the plot below (of the corresponding image: ...
0
votes
1answer
41 views

Deciphering Coding Shortcuts [duplicate]

I'm having trouble deciphering why the following couple of expressions evaluate the way they do. #&@@ This returns the first value of a list. Why? Naïvely I ...
0
votes
3answers
72 views

Constructing an arbitrary dimensional matrix with a certain rule

I want to construct the following matrix $M$ of dimension $(N+1)\times(N+1)$ with the following rule (for arbitrary N). Below, in the subscript, as usual, the 1st index gives the row and the second ...
2
votes
1answer
31 views

Encoding/Decoding matrices as integers, integers as matrices [closed]

I want to convert large binary matrices of m x n dimensions into integers, and then to convert these integers to the original matrices. I attempted the following: ...
0
votes
0answers
29 views

DeleteDuplicate from a list with {x == y, y == x} -> {x == y}; [duplicate]

How can I tell Mathematica that it should delete equal elements from a list, which aren't in the same order. For example list={x == y, y == x} ; should become ...
3
votes
1answer
38 views

Interval arithmetic for DawsonF (or other special functions)

I am currently trying to estimate a complicated expression involving DawsonF using interval arithmetic. The interval arithmetic is partially supported by ...
1
vote
1answer
33 views

Formatting the prime factorization of expressions

I have a series expansion in $x$ and $a,b$ are constants which I want to type in $LaTeX$. But the numbers/integers are pretty large (have a lot of digits) so it becomes a bit messy in $LaTeX$. ...
0
votes
1answer
35 views

Exists[ ] statement inside RegionPlot[ ] too hard to resolve?

I've got a very complicated existential boolean expression, call it $\exists x: condition$, involving variables $p, q, $ and $x$. Is there a way to plot the region in which this statement holds ...
1
vote
1answer
35 views

ListPlot3D Link Tick Range to color gradient

i am pretty new in Mathematica but upt to now i am nearly done with my first higher plot. I just want to use the whole range of my 7 z-values linked to the 7 colors in my defined blend for #3 (z) ...
0
votes
0answers
21 views

Rewriting List of Matrix Equation in Terms of Individual Equations? [duplicate]

I have a list of matrix equations M1={{a1,b1},{c1,d1}}; A1={{x1,y1},{z1,w1}}; M2={{a2,b2},{c2,d2}}; A2={{x2,y2},{z2,w2}}; sys={M1==A1,M2==A2}; which I would like ...
0
votes
0answers
43 views

What is the meaning of #, Root and & [duplicate]

I am new, but can any one tell me what is the meaning of formulas of x and y in the picture?
1
vote
1answer
45 views

Coordinates of the centers of the triangles composing a Koch snowflake [duplicate]

Let's suppose we have a Koch snowflake of arbitrary initial side length $a$, and a Cartesian coordinate system whose center coincide with the center of Koch snowflake, as shown in the figure. How ...
4
votes
4answers
174 views

Applying rules to expressions [closed]

I'm trying to write a rule that acts on any number, lists, expression and so on to turn any negative numbers positive. The simple r = n_ -> Abs[n] works ...
9
votes
2answers
98 views

Unexpected view of the Comsol result when I postprocess it in Mma

I simulated some nonlinear PDE using Comsol. Here one can find the results u=u(x,y) in the form of an Excel table with the terms ...
4
votes
0answers
56 views

Create an adequate 'training set' to train a ClassifierFunction which performs the role of the built-in `SubsetQ`

I am trying to "grow" my own SubsetQ function using Machine Learning methods. My cSubsetQ when given two lists (listA and ...
1
vote
1answer
29 views

NonlinearStateSpaceModel/OutputResponse gives doubled outputs

I want to simulate a pendulum or rather the controlled system. But NonlinearStateSpaceModel or the OutputResponse gives weird ...
1
vote
3answers
61 views

How to make a list (of data points) whose name is the same as the file name from which the data is imported [duplicate]

I have a set of files, e.g. file1.dat, file2.dat,... containing data (list of data points to plot, manipulate...) I want to do the following ...
14
votes
3answers
427 views

Generating Tuples with restrictions

I am interested in a certain subset of all tuples. Generating all with Tuples and then filtering is wasteful, and will "blow up" very quickly. For a concrete ...
1
vote
0answers
51 views

Convex and concave regions of a closed curve [duplicate]

A few days ago, in Mathematica's help, I saw a function for recognizing if a closed curve has a positive or negative radius (convex or concave) like in the picture I found on the web, but without the ...
1
vote
1answer
63 views

Monitoring a matrix with changeable elements as Manipulate in plotting [closed]

If we remember, Mathematica has an ability to show a Psudo-window of plots for monitoring the effects of some changeable parameters in the functions. For example ...
1
vote
1answer
38 views

3D Interaction when using CDFDeploy

In the following code, the 3D plot of the manipulation is interactive. ...
-2
votes
0answers
29 views
3
votes
1answer
30 views

Spacing control in export

While using, for example, the code ...
0
votes
0answers
73 views

Errro in plotting the results of FindRoot [on hold]

I would like to plot the results of FindRoot over certain range of one input. First of all I am sorry that the equation is a bit long and messy. I have tried to ...
3
votes
2answers
56 views

Abbreviated expressions in StringCases? [duplicate]

Am I missing something here? There's no support for abbreviated expressions in StringCases? StringMatchQ["MATCH", "*H"] (* ...
2
votes
4answers
55 views

Partition list into sublists of decreasing length [duplicate]

For example, I would like to partition {1,2,3,4,5} into {1} {1,2} {1,2,3} {1,2,3,4} {1,2,3,4,5} with just one line of code. ...
0
votes
1answer
36 views

Transform system of equations while leaving solution set invariant?

Consider the example system of equations syst==res where syst={x + 2 y + 3 x y, 1 + 4 x + y}; res={0 , 0}; Solving for the ...
1
vote
1answer
85 views

Draw Vectors in Spherical Shell and then Animate

I want to draw three vectors inside a spherical shell. One of the vectors will be moving, the others will be stationary. However, the animation is the next step. For now, I would like to get the ...
4
votes
3answers
101 views

incorrect exact sum of a series

Sum[(-1)^m*(1/Binomial[2*m + 2, 2] + 1/Binomial[2*m + 3, 2]), {m, 0, Infinity}] gives the right value -2 + π but the same ...
1
vote
1answer
104 views

The basic primitive recursive functions

How can the basic primitive recursive functions be expressed in the Wolfram Language? Apparently here's an example for primitive recursion: ...

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