# All Questions

105 views

### Binomial Regression where n > 1

I am not well versed in Generalized Linear Models, but am trying to use this approach to model some discrete data. I have binomial data where the sample size for each observation is the same size, ...
177 views

### Change default output font globally

I'd like to change my default output font to "Helvetica Neue" in version 10. The following shows the only thing I have found in Option Inspector, which would ...
161 views

### NIntegrate with units: unable to determine the units of quanitites that appear in the input

I want to integrate Planck's law of radiation in a certain wavelength intervall with units. I define some constants: ...
92 views

### Strange constants in a PDE solution by DSolve

I'm solving the following PDE: DSolve[F''[ξ] + (Ω^2 - M^2 Exp[2 α ξ]) F[ξ] == 0, F[ξ], ξ] And Mathematica gives a general solution in terms of modified Bessel ...
188 views

### How to assign equation solutions to variables [duplicate]

I have 12x12 Matrix with which I have to solve the equation below: ...
534 views

### representation of custom deformation on a meshgrid

I am trying to represent 2D deformations on a rectangular grid. In Mathematica 10, there is a method to solve the elastic differential equations and then represent the deformation as presented here: ...
344 views

### How can I create a minimal surface with trefoil knot as inner edge and circle as outer edge?

This minimal surface is the subject of Michael Foster's beautiful wood-turned sculpture "Inversion" (see http://breezyhillturning.com/styled-2/photos-2/index.html). In addition, how can one create 2D ...
116 views

### Plot table versus table [duplicate]

I have two tables like: nex1 = Table[l3*10^3/4*10^14, {l3, 1, 30, 1}]; nex2= Table[l4, {l4, 1, 30, 1}]; How can I plot nex1 versus nex2 so that nex1 is x axis ...
358 views

### Bug in ArcLength?

fixed in 10.1 (windows) With Mathematica 10.0.2: ArcLength[Line[{{0, 0}, {1, 0}, {2, 0}}]] ArcLength[Line[{{0}, {1}, {2}}]] (* 2 *) (* 2 *) However, ...
222 views

### Can't type in notebook in version 10

After upgrading to version 10, I sometime get into the situation that I can enter nothing to the notebook. The Mathematica seems alive but it doesn't take any input from the keyboard. I tried to quit ...
206 views

### How to find the direction of the outward normal in a point of the boundary of a 2D region?

Suppose we have a domain $\Omega$ such that RegionQ[\[Omega]] is True and ...
136 views

### ReplacePart equivalent for Associations

I have a fairly complicated Association. I wish to use/create a function such as ReplacePart to operate on certain Keys within this multi-level Association. Here's ...
342 views

I am calling ...
245 views

### GPA calculation from a set of randomly generated marks obtained

So, this is a homework question posed by my teacher: "A student has 10 courses. Find the ceiling value of the obtained marks and corresponding grade according to the following data Print the result ...
130 views

### Different results with Plot option “Evaluated” in V9 and V10

Consider this example: Plot[Table[BesselJ[n, x], {n, 2}], {x, 0, 10}, PlotLegends -> {"n=1", "n=2"}, Evaluated -> True] The results in MMA v9 & V10 ...
129 views

### Plotting Earth's position with units

I'm trying to plot the Earth position with the Sun in the origin. I have two lists like this: ...
110 views

### Help with building matrices

I am a complete beginner in Mathematica and I have a small problem. I have this three matrices (A,B and C) and with them I have to build larger matrix M which looks like this. What would be the ...
97 views

### Regression with 3 variables

I'm trying to find a function starting from its values but I can't find anything related to functions with 2 variables and I don't know how to go on. So, given this sample data, I'd like to know how ...
74 views

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954 views

### Processing a circular rainbow in an image

While on a cross-country flight, I observed what looked like a complete circular rainbow, visible against the backdrop of clouds. I took several photos thru the window with my small Nikon camera, one ...
94 views

### How to be sure I've cleaned up all prior definitions and assignments [duplicate]

Is there any general way besides restarting the kernel to make sure that nothing I've done earlier in a session will affect code I want to run now? One book suggested running ...
408 views

### Import/Export a FIT file, Fitness file created by Garmin GPS's and others

A FIT file is a binary replacement for GPX and TCX text files containing GPS and fitness data (heart monitors, etc.). Mathematica reads GPX and TCX files and represents them as XML. I would like to ...
74 views

### Searching in parameter space for a given number of solutions

I have this problem : I have some function g[a,b;x], where a,b are parameters and x is a variable. I know (graphically) that an equation g[a,b;x]=0 has zero, one or two solutions. I want to keep 'a' ...
465 views

### CUDA paclet and Mathematica 10.0.2 code problem

In Windows 8.1 64bit and Mathematica 10.0.2, I used the latest cuda paclet 10.0.1. However,following the sample code in CUDALink User Guide, the CUDAFunctionLoad returns an error. I can not figure ...
471 views

### Fullsimplify does not simplify Abs'[1.-a]

I have to simplyfy an expression involving Abs' This works: FullSimplify[Abs'[1 - a], a ∈ Reals] Sign[1 - a] but this ...
194 views

### Parallel Kernel Status

For parallel computing, the window Parallel Kernel Status shows some information on the subkernels. I can use two kernels, and which each of them I can do parallel computations. However, it seems that ...
290 views

### Fast export of large numerical data

Edit It seems that the bottelneck is not due to eigen value problem. I will esit the question soon. I have a 6000by6000 matrix which I got after some calculations. I want to get the eigenvalues and ...
108 views

### Overlapping EdgeLabels

I have to make a directed graph for a maximum flow algorithm assignment. Although I have managed to make the graph for the better part, it still needs some work. The problem is that Mathematica ...
88 views

### RunProcess with mdfind and -onlyin option

I have problems running the bash code mdfind -onlyin /some/folder my_string This works on the terminal, but if I try ...
289 views

### Unable to compute the area of region

For a set of data: ...
224 views

### Summand is not numerical at some point

I am trying to do some numerical integration with the following codes: ...
502 views

### Simple image processing very slow

I have compared the speed of some simple image processing routines between Mathematica an IDL. 1. Reading of a grey scale png image of (720,577) pixels: The image is: Mathematica: ...
67 views

### eigenvalues distribution

How does one plot eigenvalues distribution of a large matrix? I want to plot the distribution to show that the set of eigenvalues of the matrix of current interest is symmetric with respect to the ...
233 views

### Better replacement rules to perform this change of variables?

In cosmology, it is common to work with both a normal time variable t and a “conformal” time variable τ, which is defined such ...
329 views

### Monte Carlo Volume Calculation and Speed Up

I am trying to do a Monte Carlo area calculation for an irregular area defined by: $$0 \le x \le 1, 10 \le y \le 13, y \ge 12 \cos(x), y \ge 10 + x^3$$ I used the code with modifications (so I can ...
99 views

### how to get continuation of square matrices with periodic diagonal band automatically?

I want write a function that can automatically analyze any square matrices with periodic band diagonals and give continuations of them. But I can't figure out an elegant way to do this. Suppose we ...
169 views

### Filtering Query Nested Data (Dataset and Association)

I am trying to filter a nested Dataset. I have some data that looks like this (curated for this example): ...
149 views

### Export and manipulate 3D plots

How can I export 3D Mathematica plots such that I can put them into a presentation and still being able to rotate them? Is there a specific format or does it depend on the program used to create the ...
75 views

### How to fit this data to be used in NIntegrate later?

I have a list of data points that resemble a chi-squared distribution (long tailed gaussian) that I am having trouble fitting or finding an equation with. The goal is to use the fitted equation in an ...
45 views

I have this: ...
91 views

### FRED api reports all data in given month with same date

When I use the FRED package to retrieve weekly data, all of the data points for a given month have the date as the last day of the month instead of the date for the week of the data. ...
209 views

### ReplaceImageValue and ReplacePixelValue extremely slow

I have a grey scale image: and I am doing the following: bin = Binarize[image, 0.18] ...
303 views

### Sampling a phase space uniformly for a given energy?

The energy for a 1D harmonic oscillator can be written: $$E = \frac{1}{2 m} p^2 + \frac{m \omega^2}{2} x^2$$ where x is position and p is the momentum. I would like to sample phase space $(x,p)$ ...
57 views

### Nested TensorContract bug

Bug introduced in version 9.0.0 or 9.0.1 and fixed in 10.1 or 10.2 When nesting TensorContract the result I get is wrong. Input: ...
120 views

### How to fill a Marshal buffer with whitespace using NETLink

Further to Todd Gayley's answer on string handling in a DLL function, I have the following code: ...
315 views

### Creating REST Web Service with webMathematica

Does anyone knows how can I implement a REST Web Service with webMathematica? The SOAP service is well documented here and in the webMathematica User Guide. I saw that is possible to create a REST ...
71 views

### Parallel assigning to an Association

This is a simplified example of a problem I ran into. I want to count how often a subkernel executes a given computation. So, after having launched the subkernels, I construct an association with ...
119 views

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