# All Questions

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 ...
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) ...
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 ...
742 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 ...
155 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 ...
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 ...
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 ...
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 ...
90 views

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

Here is what I have tried thus far: ...
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, ...
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 ...
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[]?
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 ...
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'...
176 views

### NDSolve with shooting method

Here are my equations: ...
105 views

I have data ...
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: ...
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: ...
111 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: ...
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 ...
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 ...
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 ...
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 ...
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!
104 views

### Common subexpression elemination of complicated function by nesting using HornerForm and ExperimentalOptimizeExpression

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 ...
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, ...
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 ...
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 ...
206 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 ...
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 ...
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,...
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 ...
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 ...
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: ...
955 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 ...
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. ...
130 views

### same code different results on different computers

This very simple code: ...
179 views

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 ...
174 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: ...
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 <...
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. ...