# All Questions

167 views

### Global context not empty at startup in v10.2.0

Bug introduced in 10.2 and persisting through 10.2 or later Note that the analysis of this problem revealed a different problem than in Potential pollution of Global context in fresh kernel (see ...
148 views

### Number of divisors visualized with the QPochhammer function, how improve performance of code?

I have this code that is originally Jeffrey Stopple's code for the Riemann zeta function in the complex plane. Because I discovered yesterday that the number of divisors can be generated with the ...
20 views

### Custom drop-down list of tags for Dataset Keys similar to CountryData

CountryData produces a drop-down list of tags when you enter a string. I would like to replicate this functionality for a ...
357 views
+100

### Returning multiple results from a LibraryLink function

What is the best way to return multiple inhomogeneous results from a LibraryLink function? Imagine that the result of a single computation is several tensors of different dimensions and several ...
185 views

### Possible bug with FourierTransform linearity

Each component is easily transformed but the sum is not: FourierTransform[f''[x], x, k] FourierTransform[f'[x], x, k] ...
79 views

### How to find a cycle with a property in a graph

Let's have a graph with this edge list: edgelist = {s -> 1, s -> 2, 1 -> 3, 2 -> 1, 2 -> 4, 3 -> 2, 3 -> t, 4 -> 3, 4 -> t}; I want ...
478 views

### Efficiently compute double sum

Is there a "Mathematica Way", like Map or Apply to compute the following double sum? $\sum_{i=1}^{N_1}\sum_{j=1}^{N_2} m_i n_j \, f(\tau_{i} \gamma_{j})$ I have already stored the lists ...
83 views

### How to get the desired (equivalent) answer from Integrate?

This is the integrand: 1/beta/(2*z)/(1 - beta) // TraditionalForm Integrating with respect to z, gives ...
575 views

### Where is the “Function Navigator” and “Virtual Book” gone?

Under V9 "Help" was a Item each for "Function Navigator" and "Virtual Book" to find and one could work with it. Under V10 these Helpers are gone. Although under Documentation/English/System the ...
197 views

### Trouble with Position[] [duplicate]

I am in trouble with Position, Although my example works as expected it throws a warning. Position[{{a,b},{a,c},{a,b}}, _?(#[[2]]==b&), {1}] During ...
122 views
+50

### What's the difference between Interpolation[pts, Method -> Spline] and BSplineCurve?

Last month, I answered a question about spline interpolation,please see here Now I do the following operations ...
348 views

### Interpolation on a regular square grid spanning a triangular domain

Bug introduced in 10.0 and fixed in 10.1 Context I am trying to identify contours of a function which is sampled on a cartesian grid within an irregular (triangular) region. Here is the data ...
68 views

### upper limit with PlotStyle in GeoListPlot in v10.1

Bug introduced in 10.0 and fixed in 10.2 Let's start with the code below: ...
39 views

### “Part specification is longer than depth” warning in Position function [duplicate]

I'm working on a project which analyzes financial data. I download the price and dividend information for the SPY ETF which tracks the S&P 500: ...
137 views

### Difficulty using LUDecomposition

I'm having trouble using LUDecomposition with pivoting. I read the Mathematica help on this particular command, but I'm still lost. Take a matrix like: ...
61 views

### JacobiCN inaccuracy [on hold]

For my calculations I need JacobiCN[s,k] for s near 0 from the left and k near 1 from the ...
58 views

### Same scale for all the axes in Plot3D

I can't find this in the documentation. How do you force the same scale for all the axes when making a 3D plot? There is the BoxRatios option, but this only changes ...
2k views

### Playing with Matrix falling code in Mathematica

I was trying to create a Matrix falling code image with Mathematica. Here is my code: ...
350 views

### Mathematica Implementation of Householder’s Method

I typed the Householder code in this paper, which starts on page 7. The code is: ...
601 views

### How to implement Kemeny-Young method? (rank aggregation problem)

Prehistory I am trying to make some statistical analysis of some experimental data, arises from measurements made ​​on an ordinal scale. I faced with the problem of rank aggregation: to get from ...
147 views

### step by step interactive indefinite integral

WolframAlpha can give step by step solution for indefinite integral. There seems to be similar question but for derivatives. Is there a way that I can generate my own step by step solution for ...
251 views

### 3D Gamma function

I try to plot the following function: Plot3D[Gamma[1+0.5*(n+m)]/Sqrt[Gamma[1+n]*Gamma[1+m]],{n,0,1000},{m,0,1000}] I expect that for m=n and near to it the value ...
161 views

### How to change the font color of a variable in whole input cell

I want to track the occurrence of a particular variable in a code. So the idea is to change its color. Usually I do it in a crude way - convert the code into text and then use ...
43 views

### Solving matrix optimization

I have the following problem. Let $X_1, X_2, \cdots, X_k$ are $n \times n$ Hermitian matrices (need not be positive) given. Let a $n \times n$ positive matrix $A$ is given such that $Tr(A.X_j)<0$ ...
950 views

### Fast Spherical Harmonics radiative transfer

This is a rather specific question and I apologize for spamming you with some lengthy code. But it could be interesting for some reader and maybe you can help out, so please bear with me. I am using ...
168 views

### Why is mathematica eating a row from QRDecompostion

I'm attempting to calculate the QRDecomposition of the matrix: a= {{1,3},{0,5},{2,-8}} QRDecomposition [a] The answer mathematica gives me is: - Q which is a ...
57 views

### Mathematica requirements management [on hold]

Is there a way to use Mathematica notebook as a requirements document as it's possible in IBM DOORS ? ...
304 views

### Redefining a built-in operator

Is there a way I can redefine the || operator such that a||b will be 1/(1/a + 1/b)? Is it ...
134 views

### How to write 1.0 in InputFields with ContinuousAction and Number constraint

With the concept of user responsiveness in mind, I’ve tinkered a couple of small apps that are supposed to be eh… responsive, i.e. calculating without having to press enter. They all rely on ...
39 views

### Why can not the vector be transposed in integrating over a region? [duplicate]

Clear[x, A]; A = {{2, -1, 0}, {-1, 2, -1}, {0, -1, 1}}; Integrate[Exp[-x.A.{x}\[Transpose]/2], x \[Element] FullRegion[3]] This code raises an error ...
66 views

### Fixing “incompatible shapes” when multiplying arrays [duplicate]

A part of my notebook returns to me the following expression: ...
63 views

### Simplifying Expressions for FindMinimum

I am currently trying to apply the FindMinimum function to find the lowest energy of an expression. My current expression as of now is relatively complicated. It is the summation of 48 similar terms, ...
513 views

### How to add named characters to Mathematica 10?

It appears that native support for the Klingon alphabet has been removed from version 10: \[KlingonA] Syntax::tsntxi: "\"!(\[ KlingonA])\" is incomplete; ...
69 views

### Clean & efficient bounding box non-intersection test

I would like a quick test to tell me that segments $ab$ and $cd$ cannot intersect in the plane. If the maximum $x$-coordinate of $a$ and $b$ is less than the minimum $x$-coordinate of $c$ and $d$, ...
19 views

### Page breaks and headings in long table or grid

I have a need for long tables in a document I am producing but I am having difficulty. The printed document ends up with page breaks midway through the table which cuts rows part way through. I'd also ...
169 views

### How to make sure polygon is drawn flat in 3D?

Bug introduced in 8.0 or earlier and persisting through 10.2 or later I'm working on this SE question about pentagrams on top of dodecahedron for exercising. Both solutions are basically connecting ...
59 views

### I want a mix matrix [on hold]

I have a matrix with dimensions m x n and elements f[p, q] and another matrix with dimensions i x j and elements g[r, s]. How ...
52 views

### How to simulate a homogeneous nucleation? [on hold]

From this topic, Animating a Voronoi Diagram, I can simulate heterogeneous nucleation. Based on Voronoi diagrams, how can I use Mathematica to simulate homogeneous nucleation?
44 views

### How to get an element mesh from a region?

I've been exploring a new 3D solid commonly called the "Chestahedron" (7 faces of equal area). I wanted to find the centroid, so turned to Mathematica and found it!:) Other things of interest turned ...
89 views

### Equality of Reciprocal with Negative Exponent

I want MMA to tell me if two, rather large, expressions are equal. My minimum working example follows. I want MMA to tell me that the following is true:$$x^n = \left(\frac{1}{x}\right)^{-n}$$ I have ...
107 views

### Generating and Imaging of the water molecules with Graphics3D [duplicate]

my problem is I don't know how to generate e.g. 20 water molecules: Graphics3D[ Rotate[First@ChemicalData["Water", "MoleculePlot"], 45 Degree, {8, .5, 0}]] ...
99 views

### ImplicitRegion gives arbitrary boundaries

This question uses Mathematica 10.2.0.0. equation1 is the major unbounded region I would like to generate: ...
155 views

### FullSimplify wrongly reduces expression to zero

Bug introduced in 9.0 and persisting through 10.2 or later I get the following output with a fresh Mathematica (ver 10.0.2.0 on Mac) session ...
216 views

### How to simplify only the lowest level of a nested expression [on hold]

I have a large expression that takes forever to simplify if I apply FullSimplify[...]. The expression has lots and lots of brackets that luckily already groups ...
61 views

### How should I iteratively refine a MixtureDistribution?

I am trying to find a stopping time for a randomized simulation such that say 95% of trials that will be successful will have already finished. I would like to do this by creating and then refining ...
382 views

### Mathematica complaints that convergent integral diverges

Bug introduced in 10.0 and fixed in 10.0.2 Trying to do the integral ...
251 views

### Problem with Neumann condition in quarter disc

Bug introduced in 10.0 and fixed in 10.2 So I'm following the available examples in version 10 for FEM, The plane stress operator is shown as this ...
579 views

### Why is TextString[-0.5] a positive number?

Bug introduced in 10.0 and fixed in 10.0.2 I want to format numbers in decimal notation and chose TextString for this task. But today, when looking at the final ...