0
votes
1answer
101 views

How to count column occurrences in a matrix?

I have a matrix of data, and I want to count the number of columns that match, and have some way to organize them by frequency. But I don't want to count the entire column, but consider the matrix ...
1
vote
1answer
131 views

RegionPlot3D Empty

I am attempting to cut out holes in a sphere, circumscribed around a regular tetrahedron. To do so I define some points (p1 through p4 are the vertices of a tetrahedron) ...
5
votes
1answer
115 views

Why does the degree symbol disrupt this FrameLabel?

This plot Plot[x, {x, 0, 1}, FrameLabel -> {"x", "temperature / \[Degree]C"}, Frame -> True] displays beautifully, but exporting to PDF ...
5
votes
2answers
738 views

Tube vs. Cylinder

What is the practical difference between plotting Tubes and Cylinders? The documentation for each describe a 3D tube/cylinder around the line between 2 points....they seem identical. However, there ...
2
votes
1answer
154 views

Translating and Rotating a Region

I'm having an issue that is related to an old question (How do I plot a filled cylinder in 3D?), but it's an extension of it. The previous question details how to make 2D slices of a 3D region with ...
12
votes
6answers
837 views

Deleting Lonely Numbers From a List

Suppose I have a list of integers like so: list = {1,2,5,6,8,10,11,12,14,16,17,18,19}; I'd like a function that will take this list and return a new list with ...
1
vote
2answers
87 views

Avoiding overlap in rendering of GraphPlot

I'm trying to visualize some 'graphs' (i.e. the mathematical objects with nodes and edges) using GraphPlot[]. I am defining the nodes using objects such as ...
2
votes
0answers
86 views

How many kernels to set based on CPU?

Looks like 4 kernels are enough? My CPU is i7 4790K as given here. Does it also depend on the tasks and the codes? My understanding is that regardless what the benchmark says, I could always use 8 ...
1
vote
1answer
90 views

Adding a title that includes angle between two vectors in Graphic in Manipulate

Here is what I have tried thus far: ...
0
votes
0answers
124 views

Referring to arguments in nested functions

I am interested in executing the following command but don't know the proper syntax to distinguish between nested arguments, here at the Select[] and Map[] levels. For example, ...
1
vote
0answers
50 views

Analogue of Maple's `identify` command in Mathematica [duplicate]

In Maple there is a useful command identify that tries to find a closed form expression based on its numeric approximation. As far as I know there is no built-in ...
2
votes
2answers
96 views

Is there any way to pull interest rates, or an interest rate curve, with FinancialData[]?

Let's say I want to know the 5 year swap rate and the 10 year swap rate right now, is there a way to get this with FinancialData[]?
4
votes
0answers
257 views

Region Intersection for MeshRegion objects embedded in 3D

How can I create a logical intersection of MeshRegion objects that are three-dimensional? The RegionIntersection function will ...
2
votes
1answer
139 views

Grouping large dataset across a large range of values

I have a large data set that I would like to group based upon the quantiles of one specific column. My test data set is about 2.1 million rows by 9 columns (the actual data set will be much larger). I'...
2
votes
1answer
176 views

NDSolve with shooting method

Here are my equations: ...
1
vote
1answer
105 views

Compute Mean and Variance for Random Choice

I have data ...
0
votes
0answers
54 views

Integration problem: lrgexp

I want to calculate the following integration but it gives the error PolynomialGCD::lrgexp: Exponent is out of bounds for function PolynomialGCD. The code is: ...
0
votes
4answers
137 views

Do loop not working as expected

I am trying to get rid of data in a list. Every three elements I want to delete. Example below: ...
1
vote
2answers
110 views

Maximise a function over one parameter that is continuous, and one that is discrete

I have a function that I would like to maximise with respect to two parameters: one continuous, another which is discrete. A simple example of this might be the following: ...
2
votes
1answer
149 views

i need a swap mutation code (genetic algorithm) in Mathematica?

I'm working on GA coding to optimize the locators position in fixturing system to minimize the error in precision manufacturing.I need a code for mutation (genetic algorithm) in Mathematica. Here, I ...
0
votes
1answer
51 views

Manipulating the output of EllipsoidQuantile

I am trying to manipulate the output of EllipsoidQuantile to find the area in the next line. I can easily find the 95% confidence interval and this generates an ...
0
votes
2answers
82 views

Construct a function whose definition depends on the values of its arguments

I have to evaluate the components of a 6x6 matrix $S$. This matrix depends upon the semi-axes of an ellipsoid $a1$, $a2$ and $a3$. For various specific cases (sphere, prolate spheroid, oblate ...
1
vote
2answers
147 views

Derivative of Continuous and Differentiable Piecewise function is indeterminate

I'm attempting to analytically stitch together two linear functions with two quadratic functions. The function I'm considering, then, is a piecewise function consisting of 4 parts. Below are the ...
0
votes
2answers
70 views

How can I plot the following set?

I have a question: How can I plot the following set $$G:=\{(x,y,z)\in\mathbb{R}^3|x^2+y^2\in[0,4],z\in[0,3]\}?$$ Thank you for your help!
2
votes
2answers
104 views

Common subexpression elemination of complicated function by nesting using HornerForm and Experimental`OptimizeExpression

I want to have common subexpression elimination of comlicated functions where the elimination is done by factoring out the expressions. The result is not to be digested by a compiler, it should remain ...
0
votes
1answer
108 views

create subsubsubsection in Standard Report Style

I am working with Standard Report Style. When I press for instance Alt+5 a Subsection is generated. When I press Alt+6 Subsubsection is generated. What I want is a creation of something like Alt+foo, ...
2
votes
0answers
84 views

How can I stop PlotRangePadding from cutting off points in a ListPlot? [duplicate]

When I perform a 2D plot and want to highlight specific spots in the plane, ListPlot seems like a good idea. However once I want to get rid of the padding, my points are getting cut off. This is ...
0
votes
1answer
88 views

Mathematica 10.0: how to manipulate a plot where a line comes from a system of equations without an explicit solution? [closed]

My goal: I am using Mathematica 10.0 to draw several graphs according to different values of a number of key parameters. The graph is made of two functions. Challenge: One of the functions is a ...
1
vote
3answers
204 views

NSolve returning an empty set

Dear Mathematica experts. I am a chemist looking to use Mathematica to solve a system of equilibrium equations. I have a system of 8 polynomial (I think) equations with 8 unknowns, yet when I use ...
1
vote
1answer
152 views

Transposing X and Y on a plot [duplicate]

This question has appeared in many forms online, but none directly apply to my problem. I have a quite complicated, albeit bijective function of the form ...
2
votes
1answer
141 views

How to swap tensor indices without permutation?

Say I have a tensor of rank R, How to swap $i^{th}$ and $j^{th}$ tensor index? I do not want to use TensorTranspose because it requires to write down the entire permutation, i.e. TensorTranspose[T,{1,...
2
votes
1answer
143 views

Alt+Gr issue with Mathematica 7 on linux

I have the same issue as described in https://matteochinazzi.wordpress.com/2010/04/12/mathematica-alt-gr-issue-under-linux/ So basically whenever I use AltGr to write [ or ] in Mathematica, it ...
6
votes
0answers
65 views

VertexDelete not working on graph with VertexWeight

Bug introduced in 10.0 and fixed in 10.3 Good afternoon, I have observed an "unexpected behaviour" with VertexDelete and a graph with vertex weights. This is a minimal working example: OK ...
5
votes
1answer
103 views

Naming conflicts with Dummy variables in several packages conflicts

I'm using several packages in a notebook. In each packages there is functions defined with dummy variables. When I load the several packages in my session, i've got a warning message: ...
8
votes
2answers
950 views

Defining quantum-mechanical Bra and Ket operations

I have the following ket in the Fock basis: $\vert3, 0 ,1\rangle$, where each entry defines the number of photons in a particular mode and can take any one of the following numbers: 0, 1, 2, 3. As a ...
0
votes
1answer
1k views

Minimizing using indices, error: Part::pkspec1: The expression cannot be used as a part specification

I want to use Minimize where the variables to minimize are indices pointing into an array. Here a MWE that hopefully shows what my problem is. ...
0
votes
0answers
130 views

same code different results on different computers

This very simple code: ...
4
votes
1answer
178 views

How to solve a conditional inequality?

I am trying to use Mathematica to solve a conditional inequality. Find all (real) numbers $a$ and $b$ such that $|a| + |b| \ge 2/ \sqrt{3}$ and for any real $x$ the inequality $ |a\sin x + b \sin ...
3
votes
0answers
80 views

Obtain $\TeX$ code as in `StandardForm`

This is a question very close related to Breaking up long equations in TeXForm. Last time, because @Adam doest not present a clear goal for this problem, as stated by Massimo Ortolano there's no ...
8
votes
2answers
452 views

Generate a list of symbols for the planets

I would like to generate a list of the symbols for the planets to include in a nice table with other data. How can I programmatically generate (eg. using a pure function) the symbols from a list of ...
16
votes
1answer
368 views

Eigenfunctions of the Laplacian on an arbitrary mesh

So, I've constructed a mesh over which I'd like to find eigenfunctions of Laplace's equation with a free boundary (a zero Neumann boundary condition along the edge). Mostly because I figured an ...
2
votes
0answers
47 views

Computing an inexact derivative with some terms preserved in exact form

I am beginning to learn Mathematica and have the following question: How can I return a derivative with exact numbers instead of one involving numerical approximations? My original, single variable ...
17
votes
2answers
603 views

Can A Plot Be Overlayed With A Map?

Some brief, only slightly important background. I am doing a research project using the data from NASA's GRACE mission. I wrote a short Perl script to take two data files and find the change in ...
4
votes
1answer
60 views

GridLines in TimelinePlot do not export to EPS

The below TimelinePlot produces the proper figure within a Mathematica session, but when that figure is exported as an .eps figure (to be used in a $\LaTeX$ ...
6
votes
1answer
204 views

Need help on the proper use of a formula to produce a cambered airfoil

Following the book on "The Theory of Thin Wing Sections" page #112 describes the method to combine a camber line (i.e Mean Line) and a thickness distribution to form a cambered wing section. Data ...
5
votes
0answers
173 views

Neural Networks in Predict function

I'm trying to reproduce the result giving by a Predict function with a Neural Network as the chosen method. So, I'm training from this set: ...
7
votes
2answers
222 views

Transpose can't handle fractions

Bug introduced in 10.0 and fixed in 10.2.0 Note: Dataset and Association are new in 10.0 Related to this question, why can't <...
4
votes
0answers
115 views

Why is Transpose Dataset slow in one direction

Transpose is faster when it distributes Keys at the 2nd level of a Dataset than when it factors them out. ...
0
votes
2answers
113 views

Plotting direction fields along with trajectories

I am reading "Dynamics and Bifurcations" by Hale and Kocac, and in chapter one the following diagram is shown: Question is, how can I achieve the same plot using Mathematica? I've tried ...
1
vote
1answer
37 views

Removing vertical/horizontal edges from some cell frames

I recently asked a question regarding adjusting adjacent cells' margins to make their background color appear continuous. With these settings in place, I'd like to put a single frame around the ...

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