0
votes
0answers
5 views

CountryData function

I under that Mathematica are able to extract data from a cloud/ online sources. Pardon the improper use of jargon for programming and IT is not my area of familiarity. Are the data that Mathematica ...
0
votes
0answers
7 views

How can I plot the graph based on time from TimeUsed?

Good day everyone, Can anyone help me how to plot the result using time from computer. Here, I used timeUSed to generate the time; ...
0
votes
1answer
26 views

Large matrix: Finding eigenvalues and ordering it with respec to the highest coefficient of its eigenvectors

I have a 900x900 matrix to diagonalize. After diagonalizing it, I have a table of eigenvalues and eigenvectors. For convenience, I start with 3x3 matrix. ...
0
votes
0answers
36 views

Make integration/ plot run faster? (takes hours)

I am using Mathematica 10.0.2.0. Here is the code I am working with: ...
1
vote
0answers
20 views

Filling between two plots up to some boundaries only [duplicate]

Suppose I have plotted two functions $f(x)$ and $g(x)$ on the same plot. I would like to shade the area between the two curves only when $f(x) \geq g(x)$, but I cannot get the Filling command to do ...
13
votes
0answers
49 views

What has changed in pattern matching functions with the Orderless attribute?

In making an attempt to answer this question, we ran into a version-dependent pattern-matching issue. An extended discussion in the comments transpired, and some inconsistencies arose. Consider the ...
0
votes
0answers
37 views

Mathematica, stop sorting my output! [on hold]

I'm trying to get some output from Mathematica / WolframAlpha, but it's coming out in a useless format. Mathematica is, for some reason, sorting my output. Below is the output from my function and ...
0
votes
1answer
31 views

Max iterations for NestWhileList [on hold]

I'm writing Turing machines with a halting state. Many of these tms will never reach the halt state and I want a way to tweak NestWhileList so it runs a max of $n$ ...
0
votes
0answers
15 views

Wolfram Development Platform won't show my files

I just logged into Wolfram Cloud, so far I had no problems using it. But now, with this error when I try to open the home directory: What could be the problem? I don't have access to any of my ...
4
votes
0answers
47 views

Does Mathematica have built-in support for multivariate regression?

I know that LinearModelFit can generate a model of a single response variable as a function of a set in input variables. Does Mathematica provide support for ...
4
votes
1answer
37 views

Using Interval Slider in Manipulate for Plot Functionality

I am trying to incorporate Interval Sliders in Manipulate to allow the user to select a range to view a given plot. Here is an example that I have constructed for ...
10
votes
2answers
126 views

Converting Graphics geometry to a Graph

I need a representation of a 3D Sierpinski Gasket in a form of a graph to perform some simulations on. The 2D version is included in Graphdata[] but the 3D one is nowhere to be found, so I was ...
0
votes
0answers
33 views

What is wrong with my formulas for a mathematical model of a double pendulum? [on hold]

I wanted to create a computer simulation on Matlab, using a model for a pendulum from this study (A double pendulum model of tennis strokes. Rod Cross. Uni of Sydney, 2006) - Link I wanted to use the ...
0
votes
0answers
14 views

Problem in plotting [on hold]

What is wrong with Plot3D[Sin[x y], {x, -2, 2}, {y, -2, 2}, PlotPoints -> 30, Mesh -> True, ]; It is almost the same as here (on page $15$) with the exception that I erased the last line ...
0
votes
0answers
19 views

Evaluating Elliptic Sine function

I am new to mathematica. I want to evaluate the elliptic sine function(se_r): http://mathworld.wolfram.com/EllipticSine.html The straightforward way of doing it would be using it's definition ...
0
votes
1answer
35 views

How to solve time dependent pde?

I have set out to try and solve a time dependent wave equation with specific boundary conditions, but I am running into a bit of a snag. As you can see, I am trying to solve for the wave function u[t, ...
1
vote
0answers
32 views

\$MinNumber vs. \$MinMachineNumber [on hold]

I'm working on some code that is giving me a division by 0 error, but I don't think I'm dividing by any functions that could come out to be 0. At one point it was suggested that this could be caused ...
0
votes
0answers
26 views

Filtering bad urls from a list of image urls [on hold]

I have about 90k image urls and I'd like to Select only the ones that are real images. Map[Check[Import[#], Nothing] &, urls] would take about 6 hours. Any ...
2
votes
1answer
22 views

How does AdjacencyLists work on SparseArray

I have been working with large SparseArray and have noticed the properties are very very useful and fast. I wanted to manipulate my large sparse array in ways similar to the properties. Looking at the ...
4
votes
1answer
54 views

Does mathematica have a k-furthest neighbors?

I'd like to pick k points from a set of points in n-dimensions that are maximally apart. What is the simplest way to do this? Example: ...
0
votes
1answer
28 views

Is it possible to get same answer from NonlinearModelFit with and without errors on data? - How to insert errors in NonlinearModelFit?

I want to use NonlinearModelFit with the following data. I tried it firstly without inserting any error bar. ...
0
votes
0answers
29 views

Create n number of sliders with push of a button

I am trying to create an app and a part of it I want to plot 2D slices of n dimensional data. For that purpose I ask the user which plane he/she wants to use and change the other dimensions with a ...
0
votes
0answers
16 views

Why isn't this minimize function returning the optimal answer? [on hold]

I am trying to minimize the following equation by solving for s1, s2, s3, s4 (where s1+s2+s3+s4=20, and they should be positive integers) ...
6
votes
3answers
69 views

Transformation rule for arbitrary number of argument expressions

I am failing to write a Mathematica transformation rule that replaces e.g. f[a + 3, b + 3, c + 3] with f[a, b, c] + 3 for an ...
0
votes
2answers
28 views

If/else conditional in Mathematica

I am a beginner in Mathematica. How can I turn the following Matlab commands into Mathematica commands. ...
1
vote
0answers
40 views

How to view an image from command line?

I'm running mathematica in command line mode, but I need to view a graph/image, so I'd like to open an image with an X11 window to inspect an image: Is there an easy way or built-in command to to ...
2
votes
2answers
235 views

Building a Career Ladder Lattice (Follow up)

I want to thank you both for your help above. I'm going to abandon my quest for a number to label substitution using VertexRenderingFunction; because I need the ...
0
votes
0answers
31 views

Non commutative products and scalars

Say I have an expression such as $$a.(\alpha b)$$ where $a$ and $b$ are non-commutative operators, but $\alpha$ is simply a scalar. How do I tell Mathematica to treat $\alpha$ as a scalar and "pull" ...
1
vote
2answers
44 views

Merging Two Lists - Loops

I have 2 lists. For example, list1 = {{a,b}, {c, d}, {e, f}, {g, h}} list2 = {{1}, {2}, {3}, {4}} I want to merge them such that I get the result: ...
0
votes
0answers
12 views

Help changing InputField value [on hold]

I'm not sure what I'm doing wrong since I've had this work before, but I have the user input a matrix using InputField, with initial values defined in ...
0
votes
1answer
19 views

Element-wise SeriesCoefficient for matrix [duplicate]

I have a matrix expression which, when expanding with the Series[] command, returns $$\left( \begin{array}{cc} 1-\frac{1}{2}t^2+\frac{1}{8}t^4-O[t^5] & t-\...
2
votes
1answer
30 views

Interpolating functions and Look-up tables

This is just a general question about how InterpolatingFunctions work: If I have a complicated function that I don't want to have to evaluate many times over, does turning it into an ...
0
votes
0answers
36 views

How to delete sublist in a list?, with DeleteCase or similar

I like to delete the sublist that have the second element "" (or any other you can set as "-1" or "A") In the next example, I would like to erase the first and third sublist. How can I do this with <...
0
votes
0answers
34 views

How to change the output form of result

If you use Mathematica to do this integral: Integrate[1/(x^2 - a^2), x] you will get a uncommon function form like ...
0
votes
0answers
27 views

NMaximize — Error + Output

When I run the code, Table[ NMaximize[ {f[α, χ, τ], 0 <= α <= 2 π, 0 <= χ <= π}, {α, χ}, WorkingPrecision -> 10 ], {τ, 0.1, 2, 0.1} ] ...
2
votes
1answer
25 views
0
votes
0answers
7 views

Finding a closed form solution [migrated]

For the sequence 0 2 8 34 144 ... The recurrence relation is: $$\begin{align*} $E(n) = 4*E(n-1)+E(n-2)$ \end{align*}$$ How to calculate the closed form expression ...
2
votes
1answer
29 views

Why is tubed space curve not exported in stl files after rotation?

Following up a comment on this question, as part of some image, I want to make a tubular shape and export it for 3d printing like here: ...
0
votes
1answer
45 views

NB loading code broken in MMA 10 is there a workaround?

In MMA 9 I use the following code to load multiple nb's and close them after they are evaluated. In MMA 10 this code is broken. It appears that MMA 10 takes far longer to evaluate the code than the ...
-1
votes
1answer
40 views

How to combine Nest and list Part

I have a list $L$ of Length $n\geq6$ and a function $f$ that, when applied to $L$, generates $n-5$ lists $\mathscr{L}_i$ of Length $n-1$ (at the outermost level). I ...
0
votes
2answers
32 views

NMaximize and FindMaximum — Two Different Results

I have the following code in my preamble: ...
4
votes
3answers
71 views

Using a function from inside a module [duplicate]

I try to plot a function for special values of some parameters which I don't want to set globally: ...
9
votes
3answers
251 views

Dataset collapsing/reducing

I have a dataset ds with 3 columns named A, B, C. Columns A and B have repeated values. How can I obtain another dataset that contains a list of the values in C for ...
0
votes
0answers
11 views

Logic or mathemathic sequence [on hold]

[10,2,4,6,2,8,5] Can someone tell me the logic behind this sequence? It was a question on a magazine without the last number - 5 - but i can't find any logic.
1
vote
2answers
65 views

How can I Plot DiracDelta function with complex number?

The function is: y[w_]= 0.32 DiracDelta[(2.495*10^-21 + 0. I) + 1.054*10^-50 w] + 1.19 DiracDelta[(1.979*10^-20 + 0. I) + 1.054*10^-58 w]; Question 1) ...
2
votes
0answers
51 views

Interpolating functions and NDSolve

I've been working on trying to get Mathematica to solve this system for a while now, and I have a couple of questions relating to various parts of the system: Interpolating functions: As a number of ...
-5
votes
0answers
19 views

lyapunov versus coupling parameter [migrated]

i need a plot of lyapunov exponent versus coupling parameter graph for lorentz system.using the matlab program i got lyapunov versus time graph using programme below function ...
-1
votes
0answers
26 views

Please check my code for gauss elimination and rectify the mistake [on hold]

clc; clear all; prompt = 'Enter No of Unknowns \n' ; m = input(prompt) ; a = zeros(m,m) ; x = 0 ; for x = 1:m for y = 1:m prompt = 'Enter element(x,y) \n' ; ...

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