5
votes
2answers
268 views

Calculating displacement for a circular disc

I have to calculate the difference in diameter of two concentric circles. The image is obtained from an experiment and the data looks like this. The length required is the value of l as marked in ...
1
vote
1answer
104 views

PNG image is exported smaller size than imported

I upload a PNG file and then split it into its red, green and blue components. I then save these components. The original image is 1440 x 764 pixels, 2.21MB. But the 3 saved files are each 360x198 ...
1
vote
2answers
101 views

How to export many images within a For-loop [duplicate]

I'm trying to export a lot of files at one time with a For-loop. I'm using ToString so I can number the output files. It's not working. Does anyone know how to ...
2
votes
2answers
156 views

Updating Manipulate output from within a Button

Consider this (edit: Pause[3] represents some long computation the button should do): ...
1
vote
1answer
117 views

Creating/placing Mathematica cells anywhere

I am interested in making powerpoint-like slides using Mathematica. The most appealing thing about writing documents in Mathematica is that it is so easy and quick to type complicated formulas with ...
15
votes
2answers
349 views

Align stars in multiple images

I hope that you find this question interesting and that this will help others with similar problems as this configuration is not so particular. My problem I have multiple images of a particular ...
1
vote
1answer
138 views

Problem with NIntegrate over a user-defined region

I define a region as follows: ...
1
vote
1answer
136 views

Perceptron: Do loop not returning a value

I am trying to write a function that finds a simple best fit line for some data (Perceptron algorithm). Sadly it returns no output at all. Here's the code below: ...
1
vote
2answers
91 views

Finding roots of a function with a varying parameter

So I'm brand new to Mathematica, and basically what I want to do is find the roots of a function at varying time intervals. The function I'm using is: ...
10
votes
5answers
438 views

How to randomly select subsets

I have a list of around 300 elements. I want to sample subsets of length 25 such that my samples are all distinct. My first inclination was to use something like ...
5
votes
1answer
373 views

Obtaining an NIntegrate error estimate

Is there a way to extract the error that Mathematica estimates when calculating a numerical integral using NIntegrate? Internally Mathematica must keep track of ...
0
votes
1answer
82 views

problems with wstp32 (WSTP / mathlink)

I've been recompiling old mathlink programs in Visual Studio 2013. No major problems so far until I got to a program that is seemingly similar to the others but that fails dramatically in the linking ...
1
vote
1answer
103 views

Unit System documentation

Is there any documentation on what consists of the unit system "SIBase","Imperial", "SI" and ...
6
votes
1answer
131 views

Saving memoization to disk

I like using memoization (i.e. the construct myFunction[x_]:=myFunction[x]=...) when I have a heavy function that I need to re-evaluate on the same arguments. ...
4
votes
3answers
239 views

Using Block with a list of variables

I have a list of variables var={v1,v2}; which I want to protect/localize during a particular operation. I have decided that I want to use ...
1
vote
0answers
101 views

Implementation of Lubaehevsky-Stillinger Algorithm to pack hard spheres

To generate a model of a polycrystalline material with specified grain size distribution (e.g coming from a Monte Carlo Grain Growth simulation) the Paper "Effects of grain size distribution and ...
0
votes
2answers
165 views

Is there a function that filter positive values x = f(x), and return zero for all negative values? [closed]

I'm searching for f that will comply this definition : x = f(x) where x is natural >= 0 0 = f(x) where x is natural < 0
2
votes
2answers
224 views

Adding map to 3D plot?

I've made a 3D plot of a pressure surface over the region 160W-20W, 20N-80N - the right panel and I would like to put a map under it, probably just continental outlines for simplicity. I'm just ...
0
votes
1answer
130 views

Problems with the plot of a function. [duplicate]

For some reason the result of Plot of the following function: ...
0
votes
1answer
77 views

Interacting Dynamic Components within LocatorPane

I am attempting to create a dynamic contour plot of an ellipse with two locators as the foci within a locator pane. The following code has been implemented: ...
0
votes
1answer
83 views

Variable change

If I have the following Hamiltonian: ...
0
votes
1answer
107 views

NIntegrate vs. summation

I' m interesting in distributions of points on sphere, plane figures etc. Especially for small number of points: 1, 3, 7, ... It seems that good criterion for uniformity of distribution is some ...
0
votes
1answer
76 views
2
votes
1answer
88 views

Export a Pyramid to VRML format

How do you export a Pyramid to vrml format in Mathematica ? I have been trying to do this the following way ...
3
votes
2answers
96 views

Slow application of `Outer` on a matrix

I have some performance issue with the calculation of a gaussian kernel applied to a not-that-large dataset. I'm not very good with performance tuning in Mma and I have the feeling this one could be ...
2
votes
1answer
112 views

Plot with two LabelStyle

I need to plot a graph using two different colors for the axis labels. Not working example: ...
6
votes
2answers
215 views

There is an issue with Manipulate in which it updates its argument twice in V10

I have asked this question before (here) and I thought that the issue is only when moving the Notebook window. It appears that Manipulate is working in weird manner. ...
2
votes
1answer
177 views

Export Multiple Arrays Into a Single Worksheet with Column Headers

I'm importing financial data into Mathematica, creating column headers for each array and exporting to Excel. The code below accomplishes most of this, but it creates a different worksheet for each ...
3
votes
1answer
161 views

Mysterious spikes in Plot3D

I am using Mathematica 9 and get these strange spikes when I plot the following simple function. I have seen a previous post about this but cannot figure out what is wrong with the following code. ...
1
vote
0answers
68 views

Errors when thickness is reduced solving 2D cylindrical heat conduction equation

I am trying to solve the heat conduction equation in cylindrical coordinates with a defined heat generation within the volume (a thin disk, with different heat flux BC top and bottom). The problem is ...
2
votes
1answer
223 views

How to plot on complex plane with Mandelbrot set

I essentially want to treat the Mandelbrot set plot as a normal plot so that I can plot arrows and points on top of it. This is what I want to do but it gives me an error: ...
3
votes
2answers
751 views

How to change the font color and size of tick labels by default

I've read Mike Honeychurch's answer here, and while it tells me how to change the font size on all of my plots, that size change affects (I think) all text on the plot. I would like to be able to make ...
1
vote
1answer
84 views

Are all of the numbers in my file legitimate hex numbers

I have about 10,000 hexadecimal numbers (32 digits each) in an excel file, in one column. I want to verify that all of them are indeed hexadecimal number and that no other characters are present. My ...
0
votes
1answer
81 views

Differential equations DSolve constant issue

After using DSolve to a set of differential equations, three constants arise. They are C[1], C[2] and C[21]. I have checked thoroughly that there are no C[3], C[4],....C[20]. It is quite mysterious to ...
2
votes
1answer
88 views

Strange Issue with RowBox

Can someone explain why this notebook [RANGEWORKING.nb] ...
4
votes
1answer
127 views

Output function control and manipulation for efficient computation [closed]

I have taken note of a similar post related to modifying function parameters. I tried to adapt Kuba's solution to this post but I can't get it to work. I will illustrate my problem using a similar ...
2
votes
1answer
480 views

Show plot legends for multiple curves in one plot [closed]

I have 5 curves, figure1a0, figure1a001, figure1a01, figure1ae01, and figure1ae001,. I display all these curves in one plot with Show. I want to give a label to ...
3
votes
1answer
174 views

WSTP (formerly MathLink) problem

I recently set about to re-compile some old (2008-2009) applications that use MathLink in preparation for creating new, modified versions. Mathlink has been deprecated but WSTP seems like a fairly ...
17
votes
1answer
1k views

Is Mathematica `ContourPlot` function really so efficient?

I wanted to find the roots of the function $f(x,y)=\sin(3.2x)\sin(1.3y)-2.1 \sin(1.3x)\sin(3.2y)$. This is what the function looks like: ...
0
votes
0answers
40 views

How to evaluate NMinimize inside a function

I want to define a function that returns a sum of differences of some points to a given function. To obtain these differences I would like to use NMinimize, but if I implement that straightforwardly, ...
0
votes
1answer
50 views

Why Table is not giving me the same sequence for eigenvalues of matrix

Let consider a matrix and evaluate the time dependent eigenvalues M[t_]:={{Sin[t],Cos[t]},{t,t*t}}; e1[t_]:= Eigenvalues[M[t]] Now If I evaluate ...
0
votes
2answers
338 views

Convolution of a piecewise function

I want to find the convolute the the functions in the Convolve command ...
1
vote
1answer
62 views

Error with using SortBy in a Map [closed]

I have a data set in the following format: SomeData = {{a, 1, 2}, {b, 2, 3}, {c, 3, 4}, {b, 1, 9}, {c, 1, 10}, {a, 2, 3}, {a, 3, 8}, {b, 3, 4}, {c, 2, 9}}; The ...
10
votes
0answers
187 views

Efficient image stacking

I have a list of lists of images that I would like to stack and create mean images for each list of images. Images are .jpg files 2592x1944 pixels large. Each list ...
0
votes
1answer
68 views

Vector Analysis in Version 8

Silly question. Why does Needs["VectorAnalysis`"] Grad[Sin[x^2 + y^2], {x, y}] give the error Coordinates::invalid: "{x,y} is not a valid coordinate system ...
5
votes
1answer
131 views

Specifying WorkingPrecision in LogLogPlot produces invalid plots [duplicate]

I seem to have found a bug with LogLogPlot in Version 10. If I specify a working precision, the function produces total garbage. Here is a simple example. The first ...
5
votes
2answers
213 views

Drawing a path which realises the diameter of the graph

So I enter a (0,1) adjacency matrix and I get the following graph: The diameter of this graph is 4. How can I ask that two vertices which realise this diameter be drawn with different filling ...
1
vote
1answer
257 views

How to impose normalization condition (not initial condition) on DSolve or NDSolve?

I have a set of differential equations (or DAEs): $\begin{cases} 5x_{2} + 3x_{4} + 3x_{5} = \frac{dx_{1}}{dt}\\ 5x_{1} + 5x_{2} + 5x_{3} + 3x_{4} + x_{5}= 0\\ 3x_{2} + 3x_{4} + 10x_{5} = ...
1
vote
0answers
57 views

Is it possible to circumvent this overflow?

I'm trying to evaluate the following function numerically: $ f(A,B)=\frac{2A\pi ^{5/2} (-1)^B}{(A!)^2B!} \, _4\tilde{F}_3\left({\frac{1}{2},1-A,1-A,1-B\atop ...
1
vote
1answer
129 views

How can I copy & paste cell styles?

In Mac's mail app the key shortcut "command + option + c" gives a copy selected text style and "cmd + opt + v" pastes the style. Is there a way to achieve this with cell styles? The keyboard part is ...

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