# All Questions

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### 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 ...
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; ...
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### 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. ...
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: ...
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 ...
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 ...
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 ...
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 $n$ ...
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### 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 ...
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 ...
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 ...
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 ...
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 ...
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### 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 ...
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 ...
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, ...
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 ...
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 ...
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 ...
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: ...
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. ...
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 ...
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) ...
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 ...
28 views

### If/else conditional in Mathematica

I am a beginner in Mathematica. How can I turn the following Matlab commands into Mathematica commands. ...
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 ...
235 views

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 ...
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" ...
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: ...
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### 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 ...
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### 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: ...
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### 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 ...
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 ...
32 views

### NMaximize and FindMaximum — Two Different Results

I have the following code in my preamble: ...
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: ...
67 views

### Among several lists how to identify a pair of numbers together in a same list?

I have some lists: ...
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 ...
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.
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) ...
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 ...