5
votes
0answers
113 views

Learning Resources for Data Science in the Wolfram Language

I'm delivering an upcoming course on Data Science with the programming/analysis done predominantly in the Wolfram Language. I created the following table to leverage students' familiarity with Lists ...
0
votes
1answer
50 views

Why can NSolve only solve this system of equations after trivial substitution?

The first system immediately yields {}, but the second, equivalent, system yields the solution {{k -> 4.96048, tl1 -> 1.64842, tl2 -> 2.07466}} : ...
0
votes
0answers
29 views

What is that Root[…] inside the answer represent? [duplicate]

So I am encountering this situation, in which mathematica doesn't give me the answer, but in a form of "Root". How do I interpret this ? what is the number after the "&" represent? How should I ...
3
votes
0answers
103 views

Undirected Network and its Monte Carlo Simulation

So I have this array of points, in the form {x, {y,z}}, where x is the node number assigned when I used the locator pane to make a network, and y and z are its unitary coordinates. The graph is made ...
3
votes
1answer
87 views

Interpolation function rejected by ParametricPlot3D

I was playing around with the bouncing ball example, and decided to make a 3d version. I decided to use ParametricPlot3D for a simple independent 3D ...
0
votes
0answers
44 views

How to handle infeasible points in FindRoot?

I am calling FindRoot[f[x,y],{{x,xInit,xMin,xMax},{y,yInit,yMin,yMax}}] where for some points {x,y}, ...
6
votes
2answers
138 views

Probablity weighted ReplaceAll

I'm looking for an elegant way of doing a probability weighted replacement rule, something like this ...
6
votes
0answers
144 views
1
vote
1answer
61 views

why head Association cannot be replaced by head List [duplicate]

Consider replacing head of List by head Association: {a -> x, b -> y, c -> z} /. List -> Association (*<|a -> x, b -> y, c -> z|>*) ...
0
votes
0answers
37 views

Plotting and NIntegrate [on hold]

I have a problem. I try to make such a plot: function = y^(3/2)*Exp[I t y - y^2]; Plot[NIntegrate[function, {y, -∞, ∞}], {t, -20, 20}] But I have no plot - I ...
2
votes
1answer
53 views

Operator-Input Form for Lists?

The documentation on Operator-Input Forms shows the following example which suggests that there is an alternative, convenient, operator-style, tidy technique for inputting lists. However, there is ...
4
votes
2answers
86 views

Can NDSolve handle discountinuos data?

It is possible to numerically solve a differential equation if not-smooth data are involved? For example the following instruction return the error NDSolve::bvdisc: ...
7
votes
2answers
137 views

Backslash commands in strings?

I discovered by playing around that Text[DisplayForm@SubscriptBox["\[Lambda]", "k"]] produces the same result as ...
5
votes
1answer
95 views

Is there a faster way to Map an Association?

Consider mapping an existing Association in a manner such as this: ...
1
vote
1answer
33 views

Automatic substitution of fractions

I have several equations with many variables, and here and there I would like to do a variable substitution. For example, in the equation: a (b + 42 c / d) I ...
0
votes
1answer
56 views

Substitution in Mathematica [on hold]

I am new to Mathematica and hope to learn a lot here. Could you help me with the question below. Thanks! Here is the expression: ...
6
votes
2answers
114 views

Which function definition is used to evaluate an expression that matches the lefthand side of more than one definition?

In a case like this: f[a_] := a; f[{a_, b_}] := a; I'm wondering whether I should expect f[{2, 3}] to return ...
9
votes
2answers
164 views

Testing Credit Usage in Wolfram Programming Cloud

I currently have a free WPC account, which I am using for testing purposes. Amongst other things, I want to find out more about how the credit system works, in particular how many credits are used, ...
2
votes
0answers
32 views

Unique CellID in-between notebooks

Documentation says that CellID is guaranteed to be unique for a given notebook. I've noticed that CellID are fairly high numbers and although probabilistically speaking the odds of coincidence are ...
1
vote
0answers
44 views

Black line after ImageTrim

as shown in Image correlation I would like to detect the shift between a stack of images. Here are the images: and here the code: ...
1
vote
2answers
94 views

How do I exclude the vertical line plotted at a discontinuity?

Condsider function = Tan[1 x] + Tan[2 x] Plot[function, {x, 0, 1.5}] It has a strong discontinuity around 0.8. The problem is , if I want to find ...
3
votes
1answer
88 views

How do I plot a U- form cylinder

I'm really new to Mathematica, trying to learn some things, but I need help trying to plot this kind of cylinder, a U tube like cylinder. Tried to use an example code like this, and then vary some ...
0
votes
0answers
36 views

Solving a system of equations over a custom domain [on hold]

I'm trying to solve a system of linear equations with a large number of variables, but Mathematica is having real trouble finding solutions in a reasonable amount of time. One thing I thought would ...
-2
votes
1answer
34 views

Specifying parameters for the Ticks option [on hold]

I'm trying to use Ticks option with ListLinePlot to put ticks at 1, 2, 3, 4, 5, 6, and 7 on the x-axis the points and at 1, 2, ...
0
votes
0answers
17 views

How Construct Clopen-Compact Bitopological Spaces? [migrated]

Dear all who love general topology, In general topology we know the notion of clopen-compact spaces (introduced by A. Sostak): a topological space $(X,\tau)$ is called clopen-compact if every clopen ...
8
votes
1answer
80 views

How to get a list of all expressions in a notebook matching a certain pattern?

Suppose I have a Mathematica notebook saved to a certain location on disk. Given a pattern I need to get the list of all expressions matching this pattern that appear in input, output or print cells ...
0
votes
0answers
89 views

Improving the speed of evaluating Table with nested functions

I am a Mathematica novice working with a stack of 1024 x 1024 WatershedComponents (or MorphologicalComponents) label matrices ...
2
votes
2answers
73 views

Inconsistency of output format in `Eigenvalue`

I am bothered by the output format of the last two elements of efre. Is there a way to make these two look like the same format as the first two in ...
6
votes
3answers
166 views

A Case of DeleteCases for WeatherData

I am trying to use ListVectorPlot in combination with WeatherData and CountryData to show ...
3
votes
5answers
108 views

Providing a color function for ListPointPlot3D

Is there a way to write ListPointPlot3D expression, so when given a list of points, the the color of the points plotted is a function of the index/element number of ...
2
votes
1answer
135 views

Converting a nested for loop from MATLAB

In MATLAB I have the following series of nested for loops that update a matrix. (It's not my code, but someone else's that I'm trying to replicate - I don't know ...
3
votes
0answers
60 views

Using Mathematica to help obtain correct analytic formula for logarithm integration

I need to program into my Mathematica code the analytic form for the result of the integral: $$I(a,b)=\int ^1 _0 dx \frac{\ln(x-a)}{x-b}$$ that is valid for all complex $a$ and $b$ (but $\text{Im } ...
6
votes
1answer
88 views

Deploying to the Cloud for Public Access

I wanted to test how a simple deployed program would appear to a non-mathematica user. I did the following, from within a Mathematica notebook: ...
0
votes
0answers
42 views

1D bin packing solution with NMinimize or NMaximize (use minimal office space) [on hold]

I want to use NMinimize to solve a 1D bin packing problem. The goal is to assign a large number of staff to as few rooms as possible. The empty rooms can then be sub-let and generate income. Hence ...
1
vote
1answer
37 views

Conditions in SparseArray

I got confused by {i_, j_} /; in the following code. I didn't see an explanation in the SparseArray documentation. Can anyone ...
3
votes
1answer
42 views

Calculate geo location based on distance from other locations

Given a list of entities (or GeoPositions) and their distances from a particular location, how do I find that location's ...
8
votes
4answers
256 views

Fast method to select matrix elements based on a vector of positions

There is an operation for which I have long wanted to find a better solution. Let: a be a matrix of dimensions $m\times n$ ...
1
vote
2answers
80 views

eccentric anomaly expansion equation

I try to use this simple algorithm (paper) to calculate the Eccentric Anomaly expansion: ...
6
votes
0answers
93 views

Partial Differential Equation in Parallel

is there any native way to implement multi-core parallel solving of PDE in Wolfram Mathematica? WM 10 now supports Finite Elements Method, but it is actually useless without parallelization. Usually ...
2
votes
3answers
137 views

Zero-order interpolation not going fully around

Connected to this question, I want to do a zero-order interpolation of a bunch of datapoints which is periodic. The code I use is as follows: ...
2
votes
2answers
86 views

TrueQ returning False on true statement

Why does TrueQ return False on the following? TrueQ[Log[2]/Log[8] == 1/3] (* False *) ...
0
votes
0answers
36 views

How to correctly use PatternTest (?) [duplicate]

This works fine: {3, -5, 2, 7, -6, 3} /. x_ /; x < 0 :> 0 (*{3, 0, 2, 7, 0, 3}*) and this works fine: ...
2
votes
2answers
82 views

Utility information using FindGeoLocation in Ver.10

It is possible for some commuters to track the location of their bus, train or tram through a personalised GPS tracking device (e.g.see ...
13
votes
1answer
219 views

How can I mend this broken heart?

Try to evaluate the following code: ...
5
votes
1answer
129 views

How to slice TimeSeries data?

When retrieving curated data, v10 now returns TimeSeries objects. For example, ...
11
votes
1answer
127 views

Geographic background containing both outlines and contours: how?

I would like to create a map which will show lakes and rivers together with elevation contours and contour labels. What is the simplest way to do this with ...
3
votes
1answer
61 views

how to write TableForm expression into file?

Now I have a list stored in data as follows data = {{"Ca", 1, 1, 1}, {"Ca", 2, 2, 2}, {"Ca", 3, 3, 3}} the ...
0
votes
0answers
37 views

Finding Roots of Non-linear Systems: Rescaling polynomials

I'm trying to get all isolated finite equilibria of a moderate multi-dimensional non-linear system of equations. Particularly I have 9 independent variables and third order at most. It turns out that, ...
2
votes
0answers
39 views

How to avoid joining MathieuCharacteristicA in a plot? [duplicate]

In the documentation As a function of the first argument, MathieuCharacteristicA is a piecewise continuous function So how to avoid joining different pieces of the function? For example, ...
0
votes
0answers
92 views

NSolve for large models

I'm a Mathematica rookie running version 7.0 for Mac OS X x86 (64-bit) (February 19, 2009) on a 2010 MacBook Pro. (I'm also a stackexchange "newbie" who originally posted this on stackoverflow, thus ...

15 30 50 per page