5
votes
1answer
111 views

Strange behaviour of UpSet [duplicate]

Can anyone explain what is going on here? I want to modify TensorRank for IdentityMatrix, but it fails on its first attempt: ...
2
votes
0answers
134 views

Quartic equation [closed]

After using Solve I am choosing the physical root of my equation and dealing further with this root. However, when I am changing parameters using Manipulate, I clearly see not smooth behaviour. Is ...
3
votes
1answer
114 views

Dealing with square roots [duplicate]

Consider following expression: $$ \sqrt{-\left(2 \sqrt{x^{-8/3}-x^{-4/3}+1}\, x^{4/3}+5\right) x^{4/3}+4 \sqrt{x^{-8/3}-x^{-4/3}+1}\, x^{4/3}+2 x^{8/3}+5} $$ In code: ...
3
votes
2answers
317 views

Plot “OilReserves” using CountryData from 1985 until 2014

I am newer using Mathematica to plot with the Function: CountryData, I am trying to plot "OilReserves" in "UnitedKingdom" from 1985 until 2014. I don't know how to do it, please help me!
1
vote
2answers
185 views

Replace a value in a nested array

When I run the following, ...
0
votes
0answers
156 views

Why is Mathematica 10 giving me the junk data from Instagram?

Instagram: instagram = ServiceConnect["Instagram"] ServiceExecute[conn,"request",params] sends a request to the connection identified by conn, in my example ...
2
votes
3answers
123 views

Finding the maximum order derivative of an expression

I have an expression that is the the sum and product of undefined derivatives and their derivatives. e.g. fg+ Dt[f,t]g +Dt[g,{t,2}]f+ What I would like to find ...
4
votes
2answers
137 views

Create composite key - operating across rows in a dataset

I would like to be able to create a new dataset by extracting 2 columns to make a composite key, and also extracting other columns. For example, suppose my dataset looked like: I would like to ...
2
votes
3answers
88 views

Take a list with the amounts of the random samples from another list while holding the index

I have a list called cant with some amounts of samples to take from the list community as follows: ...
-2
votes
1answer
197 views

$SU(4)$ Structure constants in mathematica

How can I write a mathematica function which will output arbitrary structure constants of SU(4)?
9
votes
4answers
926 views

Join two datasets on keys

I want to be able to join two datasets by keys, pretty much like I'd do in SQL. I thought the JoinAcross function might do it, but it doesn't operate the way I thought. The example in the ...
2
votes
1answer
200 views

Plotting in projective space

I am having difficulty figuring out how to plot to projective space. Suppose I have a region which I have plotted such as: ...
3
votes
2answers
99 views

Running “Animate” Using a Button

I made the button below for launching an Animate, but it doesn't work at all! Why? ...
2
votes
0answers
232 views

Maximizing Large Multivariable Function over Region with Parameter Constraints

Brand new Mathematica user here. I have a complicated function to maximize, and thought I would try software like Mathematica instead of taking derivatives by hand. I found some Mathematica ...
2
votes
1answer
481 views

Solve ODE $d^2u/dx^2 + u/A = 0$

How can I solve following ODE with Mathematical: $$d^2u/dx^2 + u/A = 0 \quad (\text{or } \ C),$$ with the conditions: $$ \left.\frac{d^2u}{dx^2}\right|_{x=0} = 0, $$ $$u(x=0) = B$$ and ...
5
votes
6answers
233 views

First pair out of order

I would like to know how to efficiently determine the first pair of elements in a list that are not in order according to some predicate p. That is, list[i] > list[j] according to p, and i is the ...
3
votes
2answers
305 views

Postfix with two arguments

This must be duplicate but can't find any related post. I'm want to pas it two argument in postfix like f[a_,b_]:=a+b; 1,2//f ...
2
votes
0answers
183 views

Copy As PDF in MMA 10

Wondering if this is a known issue.. I usually export graphics and Grids using the Copy As PDF menu item. The results looked quite good in MMA 9 on Yosemite. However in MMA 10 on Yosemite, the PDF ...
12
votes
2answers
689 views

Parsing a CSV file using Interpreter

The new Interpreter functionality in version 10 looks like it has the potential to make parsing custom data formats very easy. I'm trying to create a CSV parser. ...
3
votes
3answers
150 views

Matrix manipulation

Thank you for looking and answering this question. I am trying to create a new matrix from an old one. Meaning, I have a original matrix that's 20x20. I want to keep the first five lines of the ...
1
vote
0answers
139 views

Cross-validation of a FittedModel

Although I would know how to perform cross-validation tests after fitting a model using a function like NonLinearModelFit, I wonder if there is a way to do this providing the right parameters to the ...
6
votes
2answers
104 views

ClassifierInformation's “ClassPriors” misreporting?

To the TLDR people It seems to me that when you explicitly set ClassPriors when running Classify, it creates a ...
1
vote
2answers
117 views

How to define a variable updating function? [duplicate]

I tried to program a Sudoku solver when I suddenly ran into this problem: I need a function which effectivley does this: ...
1
vote
2answers
189 views

Simulation Beta Distribution

Suppose a function such as: $\phi^{\alpha} (x,y) = \left\{ \begin{array}{l l} \alpha x & \quad \text{if $x < y$}\\ x & \quad \text{if $x = y$}\\ \alpha x + (1 -\alpha) & ...
4
votes
8answers
468 views

How to sort my list?

For example I have two lists of such structure L1 = {{"Australia",a1}, {"USA",a2}, {"Norway",a3},...} L2 = {{"Russia",b1}, {"Norway",b2}, {"Japan",b3},...} I ...
1
vote
1answer
142 views

WhenEvent “StopIntegration” problem

The first example on the WhenEvent help page is ...
3
votes
7answers
211 views

List creation/manipulation

I'd like to a create a list from A = {{a}, {b}, {c}} by taking each elements n times in the following form: ...
4
votes
2answers
446 views

Positioning Vertices in a Graph

I made a graph that has a given number at each vertex: I want to place vertex 1 above vertex 2 if value of vertex 1 is larger than of vertex 2. And also, vertices with same value should be located ...
1
vote
2answers
144 views

How to integrate a function which is only known at discrete points

I have an integration to do. I want to integrate. $\int_0^\infty sin^2(2\pi t)f(t)dt$ where $f(t)$ takes values from an array in the form $\{t,f(t)\}$ The time steps in the array is 1.1s. Can you ...
15
votes
2answers
896 views

PlotLegends -> “Expressions” not working when Plot given one function

I don't get a legend when I use the option PlotLegends -> "Expressions" when the first argument to Plot is a single function. It works OK when I give ...
6
votes
1answer
95 views

How to provide data to users in a way similar to Mathematica's curated data

How can one go about implementing a custom data backend usable by Mathematica? For example something like CountryData or ...
8
votes
2answers
453 views

What is a “Region” in Mathematica 10?

"Region" seems to be a very important concept in Mathematica's latest version. Where can one find the more thorough introductory details about the concept of Region ...
2
votes
1answer
136 views

Fix the size of vertices and arrow in graphs

I defined an option to draw nicely the graph. But I have a problem with the different size obtained. For example, the layout of the first graph is what I want to have for all other graphs I will ...
0
votes
2answers
425 views

$RecursionLimit::reclim: Recursion problem

Please, find bellow my original question. Here is all my code: ...
1
vote
1answer
261 views

Potential hill simulation

I attempted to simulate the motion of a particle approaching to a potential hill. The particle should experience a force of -1/r^2, if the equation for the ...
1
vote
2answers
80 views

Generating an Array of Vectors

I'm working a lot with nested lists of $(x,y)$ coordinates (of a FEM-like mesh, but that's not important), like so: ...
1
vote
0answers
230 views

How could I make an Excel-like table?

I am looking to build a simple Excel type of a table with four columns. I have spent some time researching Mathematica documentation, but haven't come across a way to implement that. Here is a ...
1
vote
4answers
175 views

Check if a scalar falls within the range given by sub-arrays of a matrix

I have a rank 3 matrix: r = {{{1, 10}, {19, 71}, {111, 159}}, {{1, 5}, {25, 63}, {118, 132}, {164, 185}}, {{1, 19}, {28, 49}, {157, 203}}}; and each of the ...
0
votes
0answers
156 views

NDSolve with Table and Boundary Conditions

I am trying to implement a 1D model of coupled field equations where I split up space into pieces to get a system of coupled ODEs which I call Eeqns and Ieqns. The problem I can't figure out is how to ...
0
votes
1answer
319 views

Importing Output from Linux mpstat to Calculate Aggregate and Per-CPU Averages, Creating Tables and Graphs

I'm a Mathematica noob, running a trial version for the moment, but have run into the wall trying to handle this in Excel and am looking for other options. While running a benchmark application I'm ...
8
votes
3answers
448 views

Does Mathematica have Month Range and Day range?

It is known that CharacterRange["a", "z"] gives list of characters from a to z. Does Mathematica have something similar for weekdays and months of the year? ...
7
votes
3answers
502 views

Display ALL keys in dataset

I created a dateset (estimates) with 25 keys (my columns), and about a hundred rows. I'd like to be able to list the keys from the dataset. I did this: ...
16
votes
2answers
296 views

Combining images with CUDA

SMALL UPDATE: This question is left as unanswered, because none of the existing answers as of yet actually use CUDA (though, whilst being very useful). 2nd Edition: To make it a bit more clear, and ...
0
votes
0answers
51 views

Generate all strings of fixed length from an alphabet [duplicate]

I am trying to create all possible strings of length $8$ from the alphabet $\{+1,-1\}$. I am trying to get help from this question. But not sure where to start from. Any help?
9
votes
1answer
209 views

How to save the result in the Notebook (.nb) and shut down the computer when the calculation is done

I have a notebook(.nb) which its calculation is time-consuming and long. I can not observe it if the calculation is done or not. Therefore, I want to : Save the results in the notebook(.nb) ( I do ...
5
votes
1answer
641 views

How to use MathPSfrag package in Mathematica 10?

I am interested to use LaTeX like labels in the plots that I prepare in Mathematica, and hence, I downloaded the MathPSfrag package from this website ...
5
votes
1answer
79 views

Specifying Range of RSolve

When I input RSolve[{0 == q[n + 1]^2 + 3 q[n + 1] + 2 q[n + 1] q[n] - 6 q[n] + q[n]^2, q[0] == 1}, q[n], n] I get two complicated-looking complex solutions: ...
0
votes
1answer
726 views

Using Solve but getting no output

I am trying to solve a model using a constant-elasticity-of-substitution production function, but when I try to solve the first order conditions, I just keep getting back what I typed. ...
6
votes
6answers
553 views

Convert a list of rules into 2 lists of integers

If I have a list of n number of rules, what is a concise way of breaking the data into 2 lists of the first and second part of the rule? This works, but seems like an unnecessary amount of code to ...
3
votes
2answers
136 views

Plot data as TradingChart

Does anyone know how to make a two data plot such that one of the data samples is showed as the volume transactions in TradingChart function? Thanks. EDIT: Sorry ...

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