0
votes
1answer
61 views

Manipulating of non linear differentials equation

I want to manipulate non linear differential equations $\dot{x}= x + g\, xy\quad \dot{y}= 1-2x^2-g\, y^2$ where g as parameter.but I don't get any curve on display. Plz help me
0
votes
2answers
82 views

Plotting the solution of a Chini differential equation

In DIFFERENTIAL EQUATION SOLVING WITH DSOLVE by D. Kapadia, there is a Chini differential equation : sol = DSolve[x'[t] == 5 x[t]^4 + 3 x[t]^(-4/3), x[t], t] ...
4
votes
1answer
116 views

Getting Area of a region transformed by GeometricTransformation

I tried this: Clear[b1, b2, A, p] b1 = {-1, 1}; b2 = {1, 1}; A = {{2, 1}, {-1, 1}}; p = Parallelogram[{0, 0}, {b1, b2}]; Then drew this: ...
0
votes
1answer
40 views

Plotting a dataset and its fit dynamically

I have the dataset ...
0
votes
2answers
43 views

Can you unpack a list of values into variables in a With expression?

For instance, if I am trying to draw a graph with 5 vertices labeled a through e, and I want to draw edges connecting a and b, a and c, a and d, a and e, b and c, b and d, and c and e, I would run the ...
8
votes
4answers
154 views

Replacing elements in lists of a nested list

I have the following nested list ...
0
votes
0answers
39 views

Create movies from data files [closed]

I've done some simulations of a trajectory of a particle and I have that trajectory saved in ".dat" files. Now I want to make an animation/movie and save it as GIF to include it on a presentation. I ...
0
votes
1answer
118 views

Solving Partial Differential Equations using NDSolve

I'm trying to solve the following partial differential equation: With the boundary conditions: I could use another way to resolve this, like the finite volume method, but after I solve the ...
1
vote
0answers
54 views

Problem with Volume and Parallelepiped [on hold]

This worked (copied from the documentation), and gave correct image with Graphics3D. R = Parallelepiped[{0, 0, 0}, {{1, 0, 0}, {1, 1, 0}, {0, 1, 1}}]; Volume[R] ...
0
votes
0answers
39 views

Approximation number and remove the extra numbers [on hold]

I want to approximate a number and capture it in a variable, but when I want to work with that variable the extra number that I wanted to remove in approximation gets involved. Can any one help me? ...
0
votes
0answers
51 views

How to take a list and build sets of 2 elements without duplicates?

I am new to Mathematica so the answer to this question is probably easy. I have a list of 2D-points in the form {{x1, y1}, {x2, y2}, ...} Then I have a function that will take two points and test ...
0
votes
0answers
56 views

Defining a function that depends on the length of a number and the $n$-th digit

I have defined the functions F[i][x] for i={1, 2, 3}.. I want to write a number that has only the characters 1, 2, 3, and I want ...
2
votes
0answers
64 views

Aguilera-Perez Algorithm of $nD$ rotation matrix [on hold]

I want to compute a general $nD$ rotation matrix which corresponds to a rotation by an angle $\theta$ around an $(nāˆ’2)$-dimensional subspace. I found the Aguilera-Perez algorithm in their paper: ...
0
votes
0answers
105 views
1
vote
1answer
67 views

Form with FormFunction problem

I've this form: f[a_, b_] := a + b; form = FormFunction[FormObject[<|"a" -> "Number", "b" -> "Number"|>], f[#a, #b] &]; form[] How I can ...
0
votes
0answers
34 views

How to make a Dataset a Vector or Matrix? [closed]

I have a Dataset containing some data. I would like to extract single columns as vectors so that I can perform vector and element-wise operations on them. Is this possible in Mathematica? For ...
8
votes
2answers
260 views
+100

Symbolically prove that two expressions are identical

I encountered this problem when trying to reproduce the result of this paper. (The relevant parts are all included in the preview i.e. the 1st page of the article. This link is just given as ...
1
vote
1answer
64 views

Running an external simulation program from Mathematica

I have a physics simulation program which I run through a terminal window (I use a Mac) as shown below: user$ programName inputfile.ele I would like run a ...
0
votes
1answer
110 views

Solve returns empty list

I want to solve these equations but Mathematica gives no answer. ...
0
votes
0answers
34 views

VectorPlot3D in cylindrical coordinates

I am using VectorPlot3D to plot fluid flows (in the form of a velocity field), however, I go through quite an involved process to convert flows in Cylindrical ...
0
votes
0answers
56 views

How to Extract Scatter Plot in Continuous Graph by Constant Piecewise Velocity? [closed]

Condition: inverse problem in extracting scatter plot without metrics (only relative points) from the continuous time-potential data where points are distributed with constant piecewise velocity ...
8
votes
7answers
465 views

how to get $n$ equidistributed points on the unit sphere

We can get $n$ equidistributed points in the unit circle using CirclePoints. But how do you get $n$ equidistributed points on the unit sphere(surface of a ball)? ...
7
votes
3answers
117 views

How can I draw ternary plot by these data?

I have these data and want to draw similar fifures in mathematica. any one can help me? ...
4
votes
3answers
98 views

Expanding a matrix in a set of matrices

Consider a vector $a=\{a1,a2,a3\}$. I computed $e^{i a\cdot \sigma}\qquad \sigma: {\rm Pauli\ matrices}$ and then applied the command ExpToTrig. Now I want to expand the above result in terms of ...
6
votes
2answers
180 views

Samuel inverse graphing calculator

Samuel Inverse Graphing Calculator (http://www.xamuel.com/inverse-graphing-calculator.php) is a amazing tool. Whichever be your language, you can transform a sentence in an equation. I hav try with Yo....
4
votes
1answer
120 views

Solving 2D Laplace equation for irregular boundaries [on hold]

I want to solve Laplace equation in 2D with $x$ and $y$ coordinates with the boundary conditions $V(0,y)=-180$; $V(x,0)=50x-180$; $V(x,6)=50x-180$; $V(453.595-\sqrt{450.05^2 - (y - 3)^2},y)=0$ The ...
9
votes
3answers
722 views

How to create this spikey in Mathematica?

I came across this post while messying around the StackExchange mobile. I think this thing can be easily done by Mathematica as well but I'm not an expert in geometric field. Can anyone give some ...
0
votes
2answers
150 views

How to do this 3D grid drawing? [on hold]

The idea is to make axes 3d, with a more subdued in black mesh, and shafts with their respective numbers with a maximum of 10 in each (black to print after the size of half a sheet craft, vine also ...
6
votes
4answers
170 views

Efficient way to compute a complement while respecting multiplicities [duplicate]

Suppose I have list2 which is a subset of list1. I want to get a res by deleting an element ...
3
votes
0answers
61 views

ArrayPad with vectors [on hold]

I would like to pad a nested list like M = {{{a, b}, {c, d}}, {{e, f}, {g, h}}} with some constant "vector", e.g. {0, 0}. ...
2
votes
1answer
79 views

Double Sorting a Matrix

Say I have two matrices {{0, 1, 2, 2}, {2, 1, 0, 2}} and {{2, 1, 0, 2}, {2, 1, 2, 0}} I then sort by the first row ...
1
vote
2answers
48 views

How to plot data with different colors (or symbols) depending on a condition [duplicate]

Let's consider a simple example. I want to plot a function on [0;2], depending on a condition: if x<1, I want to plot ...
3
votes
1answer
72 views
0
votes
1answer
51 views

Putting plots and graphs on a word document [duplicate]

Is there a way to copy and paste or save an image of a graph into a word document?
0
votes
0answers
50 views

Mathematica treating a system of 1st order nonlinear ODEs as a system of DAEs

I'm trying to use NDSolve to solve a system of 1st order nonlinear ODEs. The system of equations is way too long to post here, but it is in the canonical form: $x_i'(t)=f_i(t,x)$. My problem is that ...
1
vote
1answer
58 views

How to make the variables in $init.m$ not impact the autocompletion

The autocompletion is very convient in Mathematica,but it will make one annoying sometimes when you have a ton variables.I give a scene I encounter.I usually make ...
3
votes
3answers
103 views

how to update elements in a matrix with position identified in a list

I am new to mathematica. Could you pls help me on how to write this: I have a $5\times 10$ matrix, for example, ap = ConstantArray[0.001, {5, 10}] I have the ...
3
votes
1answer
57 views
0
votes
1answer
62 views

Importing Data to interpolation

I have an external file in extension XLS with looks as follows: This file can be obtained by the link below: Velocidade Angular With certainty this file is generating a list inappropriate for the ...
0
votes
0answers
35 views

How to parallelize a sequential program? [on hold]

I asked this question and I got good answers, but now when I try to make the computing in parallel with this command ...
1
vote
0answers
98 views

Differential algebra package in Mathematica

Is there any equivalent of Maple's differential algebra package in Mathematica? In particular, the Rosenfeld-Groebner algorithm has been implemented?
3
votes
0answers
30 views

Differentiation and series expansion of dot product - inconsistent results

If I differentiate a dot product, I get the result I expect D[a.b[x], x] (* a.b'[x] *) However, a series expansion of the same expression gives a very different ...
3
votes
3answers
139 views

How do we draw some auxiliary lines for typical values of the function in a 2D Plot?

I want to draw some auxiliary lines for typical values of the function in my graph like these blue dashed lines: Also, I want to put the values of the lines by the lines like above one. Do you know ...
0
votes
0answers
15 views

polarized hodge structure [closed]

With the notations in the picture blew, we define the classifying space D for the polarized hodge structures is the set of all collections of subspaces of H, how to deduce the conjugation relation?
1
vote
1answer
48 views

CUDATranspose bad result

A fairly simple experiment, I am trasponsing an identitiy (3x3) matrix, and I got a weird result. I tried also CUDADot and works as expected. The code I used: ...
4
votes
4answers
114 views

Automatically add debug contents to a program

Sometimes I'll use Print[1] or Print[n] to debug in a long loop, but it's really a boring job to add these sentence by sentence ...
3
votes
2answers
69 views

How can I find the Quandl codes for metals?

Probably not the right site to ask this, but how can I find out the Quandl codes for different commodities? For example, gold against USD? Tried "CURRFX/XAUUSD", ...
3
votes
2answers
96 views

Inverse action of Thread

I cannot find the original post now, but I'm quite sure that there's an amazing post teaching us how to do Thread on ragged lists. but my problem is how to inverse ...
-1
votes
0answers
30 views

Which one is true [closed]

A high school is made by 25 pupils, of which 13 cycle, 11 swim, and 8 go skiing. There is no one practising all three sports. In yesterday's test the sportsmen (those practising at least one sport) ...

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