# All Questions

15 views

### StringSplit on comma but ignore commas in quotes

I'm importing CSV files and some of the fields include quoted text with commas as part of the field, rather than as a field separator. What is the syntax (or alternative method entirely) to import ...
16 views

### NonlinearModelFit with indexed parameters

I have an instrument calibration problem for a multi-channel instrument. Some of the calibration parameters are common between channels, while others are per-channel. Toy example: ...
37 views

### Adding a random shock to a sine wave

I have the following sine wave generated: Plot[Sin[2 Pi*x], {x, 0, 1}] How can I add a random value to this function generated from the Guassian distribution?
79 views

### Cross product between two lists of vectors

I'm trying to create a function that does the cross product between two lists of the same dimensions, element by element. Each entry of the list is a 3D vector. Something like this: ...
25 views

### Graphics3D and Postscript

When trying to export a figure with Graphics3D to postscript, I get abysmal results seen in the attached image. The image on the left is what I see in Mathematica. The image on the right is the ...
35 views

### Waveguide along a curve

I have a parametric equation of the curve and several moving frames on it. I would like to move some cross-section (not circular) along the curve with respect to the normals of the frame. E.g. let the ...
28 views

### Get slope of linear fit

This may seem silly, but I've been crazy for the last hour trying to find a way to automate the linear fit of my data. All I need is the slope. Say I have some data ...
21 views

### How to manipulate this?

I tried to code this, but everytime I code I failed. Im not sure what I did wrong and Im fairly new to Mathematica. Can you guys check it out? ...
23 views

### Converting a string into a formatted data (to create bibitem from .bib file)

Say I have a string like this ...
15 views

### Transform an expression into a function

I have a matrix of the form Mat = {{2a, 7a},{5a, 3a},{a, 2a}} (the actual matrix is a hugely complicated one of size 64x64, but the idea is exactly the same). I ...
29 views

### Einstein summation and traditional form of partial derivative of implicit function

I am quite new in Mathematica (1 week new) and after many trials I did not manage to make my partial derivatives to look traditional way. There are few topics such as How to make traditional output ...
45 views

66 views

### How do you manipulate this in 2D

Use Manipulate to create an interactive plot that shows the parametrically-defined curve described by {x[t], y[t]} = {t Sin[t], t^2/15} for ...
25 views

### Question on Poincare section example

I'm trying to make a Poincare section. On the Wolfram Documentation Center they give an example that includes the lines ...
35 views

### Removing 1 from FactorInteger

I am trying to remove the factor of 1 out of FactorInteger, so that I can search though numbers with common factors easier. Here is what I have already: For[n = 0, n < 10, n++; b = FactorInteger[...
47 views

### Finding and plotting a parametric solution to a complicated equation (transcendental, log-polynomial)

I am trying (desperately) to find a way to solve a transcendental equation whose solution $x$ depends on non-numerical parameters $a$ and $b$. And then to produce a ...
32 views

### Changing font size and style in VectorDensityPlot

I have this: VectorDensityPlot[{x, -y}, {x, -5, 5}, {y, -5, 5}, PlotLegends -> Automatic] and want to: 1) Add a label to the column bar legend on the side ...
21 views

### How can I move he documentation to another location after install on Windows?

How can I move he documentation to another location after install on Windows? I would like to move the documentation to another partition on my Windows filesystem. Michael Hale in chat recommended ...
69 views

### Pointers in Mathematica

Does Mathematica entertain Pointers in wolfram? I have a matrix and I want to make function At such that At(MatrixName,row,col) = NewValue I am able to update the ...
100 views

### Memory leak with NDSolve

This is not the first time the question in mentionned (cf in particular this recent question NDsolve memory leak), but there seems to be a serious issue of memory leak - or am I missing something? ...
34 views

### Is there a Wikidata - based Entity system yet?

Wikidata.org seems to have a similar goal as the new Entity/EntityProperty Wolfram-knowledge base system. The differences are that Wikidata is open, promising faster expansion and fixing, but of ...
37 views

### NSolve and domain specifications

I am using NSolve to find roots to a system of polynomials that describe some chemical reactions. However, I am seeing some odd behavior when I restrict the domain. First, the basic setup: ...
33 views

### Working with WolframCloud

I'm using WolframCloud from my smartphone and I'm having trouble to select all the cells of my notebook to delete them. There is a command that selects all the cells in a notebook? I tried using the ...
164 views

### How to confirm that computation uses multiple CPUs?

UPDATE: I should have made clear that I'm looking preferably for solutions that work on a text-only interface. I've fixed this omission below. I'm looking for some Mathematica expression whose ...
39 views

### Fourier Transform for Blazed Fork Grating

I built blazed fork grating on Mathematica and the idea of using blazed fork grating instead of normal one is to eliminate the other diffracted order. So the blazed fork grating will let only the 1st ...
53 views

### Why isn't LowPassFilter working for these parameters?

First I define a function, just a sum of a few sin waves at different angular frequencies: ...
23 views

### ContourPlot with custom ColorFunction: Odd behavior of “Contours” option?

I am trying to generate a blue-cyan-green-yellow-red color gradient that is linear in Hue. The code ...
18 views

### Import[] .obj data with per-vertex colors?

There's a somewhat standard way of including per-vetex color with obj files: Geometric Vertex A vertex can be specified in a line starting with the letter "v". That is followed by (x,y,z[,...
40 views

### Remove columns basing on binary sequence

Possibly it is duplicate, still I could not find here elegant way to remove matrix columns basing on binary sequence. i.e. if I apply {1,1,0,0,1,0,1} to matrix it should delete columns 3,4 and 6.
85 views

### How to generate a Markov Matrix efficiently

A Markov Matrix is a square matrix,which have two features: All elements great than or equal to $0$(But I hope all element great than or equal to $0.1$) All the columns add up to $1$ I have a ...
44 views

### How to speed up NIntegrate when using an interpolating function output from NDEigensystem?

I have been working with NDEigensystem in order to find the resonant frequencies of different shaped drums. I would also like the coefficients of the different eigenfunctions so that each of these ...
33 views

### Running complex functions in parallel

I've got a module containing a loop and multiple calls to other functions, i.e. ...
53 views

### Helping Solve to solve

I am developing quite an involved bit of code (for me) that is not finding solutions with Solve when it should. The relevant part of the code is ...
109 views

### How to 3D-plot with specific ranges?

I have the following function which I want to plot using Plot3D: (-1 + w + 3 s w)/(2 (-1 + w + 4 s w)) , which is only ...
75 views

### Web Browsing Automation: how to expand all comments under a blog post?

I wish to expand all the comments under a LiveJournal post for the purposes of saving the complete thread of comments. According to LiveJournal's FAQ when a post gets more than 50 comments they are ...
28 views

### Priority on Fitparameters

I try to fit a function using the FindFit expression. My problem is that ZL has to be ...
47 views

### Surface fitting involving factorial function [on hold]

I have a large data set made up of triples, (x, y, f(x,y)), x, y and f(x,y) are all integers. I don't know the function f(x, y) and my goal is to find (estimate) it. I do know that x can be any ...
55 views

### Problem with a chemical optimization problem [on hold]

First of all, I want to say that I'm quite new to Mathematica. I searched a lot on this site to learn how to solve my problem, which this is the problem of my life! I want to minimize a function. It ...
38 views

### Replicating same output in Mathematica from Matlab [on hold]

I have a code in matlab: ...
I generated a 2d random array in $x-y$ plane with L = 10; random = Table[{x, y, RandomReal[{-1, 1}]}, {x, 0, L, L/10}, {y, 0, L, L/10}]; Now I want to save it ...