0
votes
1answer
45 views

Plotting based on all previous equation results [on hold]

I have a plot Plot[40500*x^(-0.1), {x, 1, 100}, PlotRange -> {0, 50000}] Now, I am trying to plot the cumulative of these y values. I'll try to explain on an ...
0
votes
0answers
38 views

How to convert a rational parametric plane curve into implicit form?

This problem is generated from another Green's theorem related question of mine. And here is a forward of the same problem in math.stackexchange. The original equation of the plane curve is not in ...
3
votes
4answers
269 views

How to Find “n” for n-th Triangular Number

For example, the 7th triangular number is 28. How do I create something that will tell me that 28 is the 7th triangular number? This is what I have created. ...
8
votes
0answers
99 views

How can I smooth a 3D surface generated by RegionBoundary?

I have a set of points that belong to the surface of an object. I would like to approximate a surface to which I can compute the distance. of other points. With the nice code of this post, I was able ...
1
vote
1answer
75 views

How can I convert a fraction to a string that can be used in a file name?

I want add an index to the file names of my exported images, so I'm using ToString. But I have a problem when my index is a fraction, because then the generated ...
1
vote
1answer
54 views

Mathematica computes wrong eigenvectors? [on hold]

I have a matrix M = {{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, b}, {0, 0, -b, 0}} that I want to diagonalize. So far, I always used the following and it worked, but ...
-1
votes
0answers
54 views

How to make async functions? [on hold]

Considering we have two functions func1 and func2: func1 func2 How can I make ...
0
votes
0answers
14 views

Selecting elements from list based on list of positions [on hold]

I have a list with elements I want to select: list = {1, 34, 98, 4, 5} Now I want to select elements of those list based on a list with positions like: ...
5
votes
2answers
153 views

How to Write Partition with Infix?

The documentation says that using Infix ~, the following input f[e1,e2,e3,...] can be rewritten as ...
0
votes
2answers
89 views

Problem with NDSolve: derivative interpreted as square [duplicate]

I am using Mathematica 9, and trying to solve a very easy differential equation with NDSolve. The code I have is s=NDSolve[{y'[x]==y[x],y[0]==1},y,{x,0,1}] but I ...
0
votes
0answers
34 views

steady state of coupled partial differential equations

I need to solve coupled differential equations(occur regularly in Phase field theory), \begin{eqnarray} \tau \frac{\partial \varphi}{\partial t} &=& W^2\frac{\partial^2 \varphi}{\partial x^2} ...
-1
votes
0answers
30 views

Differentiation and integration [on hold]

When I differentiate y, I get: $$y=(x+1)^2$$ $$\frac{dy}{dx}=2x+2$$ When I try to integrate this differential I get: $$y=x^2+2x+C$$ I see that this is incorrect, but I don't understand why. How in ...
2
votes
1answer
99 views

Help me export high-resolution TIFF figure

I have generated a figure in MMA by ContourPlot3D. How can I export this figure in high-resolution TIFF format(say, 1200 dpi for lines, 300 dpi for halftone and ...
2
votes
1answer
77 views

Error accumulation in NDSolve?

I'm trying to solve this system of ODEs numerically: $$\vec{Q} = \vec{P} \times \vec{Q}$$ where vectors $\vec{P}, \vec{Q}$ have 3 components: $$\vec{Q} = \left( Q_1, Q_2, Q_3 \right) $$ $$\vec{P} = ...
-1
votes
0answers
44 views

Problem with distinguishing terms in a sum

I am doing a sum and the code for this is given as ...
0
votes
2answers
38 views

Notebook cells space on disk profiler

I have one single notebook with more than 500 mb... To control its growth, I would like to have a profiler of used space (not the live memory, but the space on disk), in such a way that I can easily ...
4
votes
2answers
93 views

Simplifying expression with non-commutating entries

Say I have an expression such as (a + X)**(b-Y) where the variables above possess the following commutation relations [a, b] = [a, X] = [a, Y] = [b, X] = [b, Y] ...
3
votes
0answers
47 views

Why does FreeQ seem not to work with complex numbers?

I guess I do not understand how Mathematica evaluates this simple expression inside FreeQ ...
5
votes
1answer
70 views
7
votes
3answers
228 views

Copy/Pasting a Grid of Numbers from Project Euler

On Project Euler Problem 11 (link: https://projecteuler.net/problem=11), there is a 20x20 grid of numbers. However, when I pasted it into Mathematica, I got this strange result where the times symbol ...
3
votes
3answers
154 views

Matrix with known entries but unknown size [on hold]

I am trying to perform some calculations with a matrix that has let's say size N but unknown, please How can I write this in mathematica?
3
votes
1answer
25 views

How can I get the vertex labels of an existing graph?

For example, if there is a graph g = CompleteGraph[5, VertexLabels -> {1 -> "v1", 2 -> "v2", 3 -> "v3", 4 -> "v4", 5 -> "v5"}] How can I later ...
5
votes
2answers
93 views

Can the increment in Manipulate, Table, Range, etc. be subject to an If statement?

In this demonstration I'm working on, I would like to plot a piecewise function with the tangent line to the function at a point that is determined by c in the code ...
3
votes
1answer
77 views

Where can I access documentation for old versions of Mathematica?

Some documentation of functions available in old versions of Mathematica (and old packages) is available online, e.g. http://reference.wolfram.com/language/Combinatorica/ref/Vertices.html Is there ...
3
votes
3answers
129 views

Calculating $\lim_{x\to 1} \, \int -\frac{i \text{Li}_2\left(x-x^2\right)}{\sqrt{3} \left(x-\frac{1}{2}-\frac{i \sqrt{3}}{2}\right)} \, dx$

How can we force Mathematica to compute this limit? $$\lim_{x\to 1} \, \int -\frac{i \text{Li}_2\left(x-x^2\right)}{\sqrt{3} \left(x-\frac{1}{2}-\frac{i \sqrt{3}}{2}\right)} \, dx$$ It seems it ...
0
votes
0answers
47 views

Is there any way to perform an ANOVA test given $n$, $\bar{x}$ and $S^2$?

Suppose I have the following data about the incomes of residents of three cities. $$ \begin{array}{|l|c|c|c|} \hline & n & \bar{x} & S^2 \\ \hline \text{City A} & 10 & 2.8 & ...
2
votes
0answers
73 views

Converting integral equations to differential equations

I am trying to use Mathematica to convert integrals to differential equations, of any order. An example of an integral equation is given below, in Mathematica code. Could you please advise as to the ...
2
votes
2answers
92 views

How to remove multiplicities from for a list in way meeting special criteria

I have a list of pairs, tabul, which has the property that the second element of each pair is also an element in my list data. I ...
14
votes
1answer
840 views

my Mathematica has turned orange and not able to find out why

I do not know what happened. But when I rebooted my PC, now Mathematica comes up orange colored. I shut down the PC and tried again, it is still orange. Here is screen shot: I also did a reset. ...
2
votes
2answers
103 views

Plotting a set of points given by a complex expression [closed]

A have the set consisting of the complex numbers $1+3r \cosθ−ir \sinθ$, where $r∈[0,1]$ and $θ$ may vary between $0$ and $2π$. This is my first encounter with Mathematica, and am having difficulty ...
0
votes
0answers
29 views

Finding the diagonal matrix of coefficients for a nonlinear set of equations [on hold]

Suppose we have $ \widetilde{k_1} $ and $\widetilde{k_2} $ in term of $k_1$ and $k_2$. We want to find a matrix that relates this variables to each other. Here is the relations. $$ \widetilde{k_1} ...
0
votes
0answers
44 views

How to use NDSolve to solve the system of differential equations? [closed]

Reference: Mathematical model for HIV/AIDS with complacency in a population with declining prevalence from http://downloads.hindawi.com/journals/cmmm/2006/471467.pdf I found the differential ...
0
votes
1answer
27 views

Compute complete graph and make minimum spanning tree

I'd like to plot a complete Graph and then compute the Minimum spanning tree of it. I already can make a complete graph out of a list that countrydata gives me: ...
5
votes
2answers
108 views

How to export images in EPS format that can be opened in CorelDraw

I am preparing a paper. The journal requirements are odd: only eps files for pictures are accepted. All pictures I have drawn in Mathematica and exported in eps format in the usual way: ...
0
votes
0answers
43 views

Comments including LaTeX commands in Mathematica [duplicate]

I want to write some comments in Mathematica - which include LaTeX commands - using the form ...
4
votes
1answer
104 views

How to check the option value?

Given that I have a function func as follow: To check the value of options, I using the step-by-step method If[] ...
7
votes
4answers
187 views

How to Apply Functions to Lists with Many Curly Brackets?

For example, consider the list defined below. samplelist = {{{1,2,3,4}}, {{5,6,7,8}}}; How would I apply the Times operator ...
0
votes
0answers
27 views

FoldList[Union,…] version 8 vs version 9 [duplicate]

I have a list of matrices something like shown below A = {{{1,1,1,1,1},{2,2,2,2,2}},{{3,3,3,3,3},{4,4,4,4,4},{5,5,5,5,5}}} When I try to run the code ...
0
votes
0answers
165 views

Why does my calculation of a probability take too much time?

I am calculating the value of the following function for given argument values: ...
0
votes
1answer
50 views

Functions becoming undefined when evaluated

I'm so confused I don't even know how to phrase my Question title. My function nextCol works until I use colLength, then ...
3
votes
2answers
47 views

Faster use of Condition for a large array (see the example)

Here is the example/problem. I have a array of $n$ random number. n = 2000; p = RandomReal[{0, 9}, n]; I have to create a $n\times n$ sparse matrix with ...
0
votes
0answers
45 views

Solving a system of nonlinear equtions [on hold]

I'm trying to solve a system of nonlinear equations which consists of 12 variables and 12 equations. A solution is obtained, but with an error. FindRoot::lstol: The line search decreased the step ...
0
votes
0answers
36 views

Why doesn't Mathematica support Import for SWF files? [closed]

Why doesn't Mathematica support Import for SWF files? I saw that Mathematica can export to .swf, but I wonder why it does not import .swf files?
-1
votes
0answers
45 views

Building Pythonic Programming style to Mathematica with visually-accessible list comprehensions?

The question List comprehension in Mathematica has comment about this Functional style using lazy lists? where they build some sort of style for lazy lists: I understand it so that it is impossible to ...
4
votes
3answers
87 views
4
votes
2answers
50 views

Building up a sequence dealing with a complex recursive scheme

Suppose I have multiple lists, the first one contains 2 elements, the next one 4 elements, the next one 8 elements, and so forth. Let these elements be labeled as Gij where i refers to the list it ...
0
votes
0answers
30 views

Optimization over 6 vectors

Suppose I have an expression which depends on 6 unit vectors (3 dimensional). Hence, I need to optimize over 12 parameters (every vector contains 3 parameters, but one we can reduce by considering ...
3
votes
1answer
79 views

How to tell Mathematica that my variable is a scalar

In my calculations I have these combinations PauliMatrix[1].f PauliMatrix[2] where f is a scalar function. The result is as ...
3
votes
1answer
65 views

How to get the size of a specific image in the front end?

The title pretty much says it all. One possible point of confusion is that this question is not limited to items with head Image. I don't know what is the ...
4
votes
2answers
72 views

How to scale multiple graphics to preserve relative sizes?

I'm looking for a simple way to make the displays of different Graphics expressions accurately reflect their relative sizes. (By "simple" I mean that it does not ...

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