0
votes
0answers
3 views

read and process hundreds of files txt

This short code is the one that broke my head for a while, are 11 variables that must meet a very specific condition, their difference must be 1. either can take the 11 values, hence all permutations, ...
0
votes
0answers
10 views

why Accumulate performs siginificantly different for two data sets with the same structure and length

I used Accumulate to calculate partial sum for two lists of vectors. These two lists have the same dimension (same number of vectors, and each vector has three ...
0
votes
0answers
5 views

Make a time IntervalSlider in Mathematica 10

Need to make a time intervalslier which start point is (10:00:00 Mar. 8 2015, 12:30:00 Mar. 8,2015) and varied from 00:00:00 Mar. 8 2015 to 252:30:00 Mar. 8,2015 for every 5 Minute. By using ...
3
votes
0answers
28 views

How to integrate Mathematica with other software

Mathematica is a fantastic platform for Mathematical analysis, physics, quantitative finance and most realms of scientific work. However, it doesn't serve well for general purpose programming, in ...
1
vote
1answer
14 views

How can i get the Style of a CellObject?

I want to work on a notebook programmatically with CellObjects. lets create a notebook for example: ...
0
votes
0answers
14 views

find initial condition for NDSolve

I have a complicate second order differential equation to solve numerically (too complicate to be posted). Unfortunately I do not know the behavior of the solution $\theta(r)$ near $r=0$ and I am not ...
0
votes
0answers
26 views

Is the letter “s” special in Mathematica? [duplicate]

I'm finding that the two versions of the expression below evaluate differently: ...
1
vote
2answers
34 views

Coordinates of MeshPoints

The output of a set of differential equations solved with NDSolve produces a series of curves and I need to obtain the spacing between these curves at a given level ...
1
vote
0answers
28 views

What is the exhaustive list of categories and properties that ImageIdentify can output?

I'm looking for a complete list of ImageIdentify's outputs. I'm seeing entities like the one below, so I'm wondering what all possible classes are if they have ...
4
votes
2answers
456 views

No weekends please

I need to get the DateValues of the last 30 days (starting from yesterday, not today!) excluding saturdays and sundays. I want that the dates are german time (GMT ...
2
votes
1answer
18 views

Dialog-type notebook

I have the following dialog to calculate the product of a and b: ...
2
votes
3answers
80 views

How can I get from a list of characters representing a permutation to graphics showing the cycles?

I am trying to graphically represent cycles in various permutations of the alphabet, and have a question in two parts. I have ...
0
votes
1answer
38 views

Plot a parametric equation in cylindrical coordinates

I'm looking for a way to plot this parametric equation on cylindrical coordinates. r = e^t theta = t+1 z = e^2t Any help would be appreciated
0
votes
0answers
33 views

How can I increase plotting resolution with RegionPlot3D?

I am trying to plot a region with RegionPlot3D, but I have some problems. Here's the code I use: ...
0
votes
0answers
15 views

same variable name is persevered as different variables in to different places in single code

So I am writing a simple strait forward code and it seems as if Mathematica is perceiving the same variable as to different ones. The code is this: ...
1
vote
1answer
69 views

Poisson PDE in a rectangular domain

I found a solution for this problem, but this is in Scilab and I never use Scilab. Can anyone can help me to translate it in Mathematica? Here is the Link:http://imechanica.org/files/TorqueR.pdf I ...
4
votes
6answers
138 views

How to check if two nested lists have the same structure?

How can I check if nested lists like these have the same structure: ...
0
votes
1answer
25 views

Function for importing and plotting data from excel spreadsheet

I know this must be a very basic question, but I could not find any answers. I need to create a function that: 1) imports data from an Excel Spreadsheet, 2) assign specific information from this xlsx ...
1
vote
1answer
31 views

Multivariate Exponential Distribution in Mathematica

Is there a way to define a multivariate exponential distribution based on independent univariate exponential distributions (Akin to multinormal distribution): ...
0
votes
0answers
28 views

How can I translate ExpIntegralEi (Mathematica function) in Matlab? [on hold]

after integration process Mathematica provided results that include the ExpIntegralEi[z] function. How can I translate this function in Matlab for $z>0$? Or ...
0
votes
0answers
26 views

numerical integration with parameter

Now I'm trying to integrate a function numerically. But it shows always an error message. x=y is not a valid limit of integration I know that this function ...
0
votes
0answers
32 views

Plot a partition of the sphere given vertices of polygons

I saw in this question that Mathematica can draw spherical triangles. I guess something similar can be done to plot a spherical polygon. I am interested in something similar: I have a set of ...
2
votes
1answer
41 views

SameTest issue?

Folks, I am trying to construct and algorithm which finds all of the remaining groupings (of three items, in this case) from a list of items for which no two items are in groups that have previously ...
2
votes
2answers
97 views

How to make a time slider like Manipulate[n,{n,1,20,1}]?

I want to make a time slider varied from 12:00:00 Jan 1,2015 to 22:30:00 Jan 1,2015 for every 5 minute. So like using Manipulate[n,{n,1,20,1}], ...
4
votes
0answers
32 views

How to speed up auxilary DooliitleDecomposite function?

The Dooliitle Decomposition algoirithm as below: $$A=LU$$ where $A= \begin{bmatrix} a_{11} & a_{12} & \cdots a_{1n}\\ a_{21} & a_{22} & \cdots ...
0
votes
0answers
29 views

Counting and updating a subset of matrix [on hold]

I have an n by n matrix and would like to count the number of sub-matrices that is equal to a given matrix. Here is my code: DWBCL creates a matrix with elements a1, a2 and c2 in it. ...
2
votes
1answer
50 views

What is the meaning of two square brackets in function definition? [duplicate]

I came along the following function definition f[a_, b_, c_][r_] = ... with some function on the right hand side. Is this equivalent to ...
0
votes
0answers
54 views

How to calculate the approximate entropy of a list of data? [on hold]

I've borrowed code from a website, because I do not know how to program in Mathematica. This code calculates the Approximate Entropy of Pi. ...
2
votes
2answers
57 views

Why is there always a horizontal tail line on the parametric curve?

I am trying to create a smooth, piecewisely continuous and differentiable curve by using Mathematica's Floor function, which is as in: ...
0
votes
1answer
14 views

Barlegend with a different z span for ListDensityPlot

I would like to rescale the colors in a plot and to do this in the same way for the color bar. (So this enables me to have the color bar span a (z) range larger than than the data itself.) I got this ...
-3
votes
0answers
42 views

ALGEBRA QUESTION HELP PLEASE [on hold]

I am really stuck on this maths question, please can someone give me the answer and how to work it out ASAP please? The question is x - 9 = 24 I need the method of how it was worked out and also ...
0
votes
0answers
20 views

How to Fit a Generalized Pareto Distribution to data in Mathematica

I'd like to know how to fit a Generalized Pareto distribution in Mathematica to implement the Peak Over Threshold method for tail estimation of operational risk losses. Does anybody have a toy example ...
1
vote
1answer
29 views

Adding extinction factor to Monte Carlo analysis

I'm looking to add an absorption component to this monte carlo analysis, essentially i want there to be a 1% chance that a photon gets absorbed at each event as it travels through the medium, once the ...
0
votes
0answers
17 views

How to create a big jacobian matrix function over some variables of a vector function?

Suppose I have a vector function of $n$ components and it has $n+m$ arguments, $$\vec{f}(x_1,x_2,\dots,x_n, y_1, y_2, \dots, y_{m})$$ where $n, m $ are around 10. I want to create a Jacobian matrix ...
1
vote
2answers
47 views

Filling a matrix with a list of lists

I have a list of lists with different lengthes: {{a1,a2},{b1,b2},{c1,c2,c3},...} Now I want to create a matrix the following way: ...
-1
votes
1answer
27 views

Not plotting elliptic intgrals

Integrate[1/Sqrt[mu^2 - Cos[t]^2], t] CenAng[t_, mu_] := EllipticF[t, 1/(1 - mu^2)]/Sqrt[mu^2 - 1] ParametricPlot[CenAng[t, mu], {t, 0, Pi/2}, {mu, 1.01, 3}] ...
1
vote
0answers
36 views

How to restart a Clock

The code below is to demonstrate color afterimages. The user chooses a color, fixates the changing numbers at the center until they reach 30 (seconds), then manually switches to white to observer the ...
0
votes
1answer
43 views

Splitting a polynomial into sum of factors, not necessarily linear

How can I split a given polynomial as sum of factors in Mathematica? For example, let's say I have this polynomial: $2\cdot x^2+7\cdot x+2$. I would like the output to be $(x+1)(x+2)+x(x+4)$. Is ...
0
votes
0answers
34 views

Plotting stellar spectrum from FITS file

I would like to make a plot of wavelength v. relative frequency from the stellar spectrum data in a FITS file (in order to fit a curve to one of the spectral lines). I used ...
-1
votes
1answer
54 views

Defining a function that resembles another function [on hold]

Given $f(x)=(4 x^{7/5}+x^3-\sqrt{x^2+1}-x+7)/(-5 x^{9/5}+x^{5/4}-x^2-3)$, Im trying to define a function $g(x)$ that resembloes $f(x)$ as $x$ values increase without bound (that is, as ...
0
votes
1answer
40 views

Unexpected results from output with NumberForm and ScientificForm

I wrote this little function to help me export tables with formatted numbers to files: (By the way, if you have suggestions on how to make it more efficient and compact, it would be great) ...
0
votes
0answers
34 views

Trying to plot solution curves on top of a direction field

I'm trying to do some diff. eq. homework that requires taking a general solution to a differential equation and graphing a series of possible solution curves over a direction field of the general ...
0
votes
0answers
16 views

Creating Group Open/Close Button [duplicate]

So I have a mathematica file with calculations and explanations seperated by groups into different sections. I want to know how I can add that open/close traingle button for Each group. This is the ...
3
votes
2answers
215 views

Convert a list of hexadecimal numbers to decimal

I know that to change a single number from hexadecimal representation to decimal, you can use: base^^digits. However, if you have a list of numbers, Mathematica ...
2
votes
2answers
52 views

How to apply list of values to a list of functions

I have the following: first= {1+a,2+a,3+a,4+a} and a list t={0,1,2,3} I want to evaluate the first element of "first" at ...
1
vote
1answer
35 views

Matching x,y,z,2

I have a list of integers; I would like to replace anything of the form $x,y,z,2$ in such a list with $x+1, y+1, 0, 0$. The problem is that the $2$ may appear at the front, or in the first three ...
1
vote
1answer
64 views

interactively replace pixel value

I am trying to develop an "Eraser" tool for imagery as is available in other image editing programs so I can interactively clean up minor defects in imagery by simply mousing over them to set them to ...
0
votes
1answer
23 views

How to add pattern or write numbers on a cylinder? [duplicate]

I want to draw several cylinders in Mathematica. In order to distinguish them in a grey-style print, I should write a visible number on or add a different pattern (dotted, lines, stripes, etc.) to ...
0
votes
1answer
29 views

Calculate the partial vapor pressures of a variable at xB = 0.75 based on the interpolation functions of the data

I'm having troubles in solving an exercise for an assignment in my Chemistry course. Talking about interpolations, I've already have a graph but I need to:(c) Calculate the partial vapor pressures of ...
1
vote
2answers
47 views

Grid versus GraphicsGrid use cases?

It seems that both Grid and GraphicsGrid can display graphics. Following the documentation here ...

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