0
votes
0answers
74 views

Fitting Data using GeometricBrownianMotionProcess

I am trying to fit Data (see below) using a GeometricBrownianMotionProcess, and have attached two figures. One figure is that of the Data, and the other of the GeometricBrownianMotion for given ...
1
vote
2answers
46 views

Substituting a list of values into a function [closed]

g[p_] := Mod[19^(-1 + p), p^2] This is my function, and the set of values I have is the first 999 prime numbers. I made a table listing the first 999 prime ...
0
votes
0answers
24 views

Point Calculation Mystery - Mirror axis at 45º? [closed]

I've calculated a point in my map view using the users position, the bearing, and the distance to that point with the help of that post: ...
3
votes
0answers
60 views

Refining a density plot of the Eisenstein series argument

Thanks to amazing code from "Guess who it is" here: Eisenstein Series in Mathematica? I'm able to make some nice plots using Eisenstein Series. What I'd like is a color plot of the argument of certain ...
1
vote
0answers
32 views

Transfer function in recursive form

To get transfer function in recursive form, I tried this: ...
1
vote
0answers
56 views

GraphDistance gives incorrect result in weighted multigraph [closed]

There are bugs in Graph on Mathematica 10.1. For example, ...
5
votes
1answer
77 views

How to make Play scrubbable?

For longer audio clips, the functionality provided by Play or Sound is clunky. I find myself wanting to scrub through with a ...
2
votes
1answer
61 views

Three Dimensional Plot of Numerical Integral with Delta Function

I want to plot the definite integral of the following function ...
1
vote
2answers
40 views

Converting data set from one form to another

I wish to convert Data to Data2. Both sets are provided below. Note that the second set has an arbitrary parameter "t". How can this be done. ...
24
votes
2answers
208 views

How can I evaluate untrusted Mathematica code in a sandbox?

Is there any way to build a sandbox to evaluate untrusted Mathematica expressions in order to prevent them from having (malicious or accidental) harmful side effects? Context: I'm developing a system ...
0
votes
1answer
43 views

How to simplify noncommuting multiplication of KroneckerProducts

I'm using NCALgebra. I was wondering if there is a way to simplify KroneckerProduct[a, b]**KroneckerProduct[c, d] to become: ...
3
votes
4answers
58 views

CoefficientList with multivariable [closed]

Consider: t = (1 + x)^3 (1 - y - x)^2 Expand[t] Now: CoefficientList[t, {x, y}] The output is: {{1, -2, 1}, {1, -4, 3}, ...
4
votes
0answers
45 views

How to set a property in an object with association syntax?

I have a simple object orientation example using this solution: ...
2
votes
1answer
63 views

Simplifying the result of DSolve

I have a system of differential equations that can be solved with DSolve. However, the coefficients are very long there are like terms which can be combined. I used //FullSimplify in my code but the ...
9
votes
2answers
215 views

Pattern and Orderless function

I'm a Mathematica beginner. I am exploring the use of patterns and (only for fun) am trying to implement a permutations function. My (dirty) code is: ...
3
votes
0answers
58 views

Possible bug in fetching price index data?

I seem only able to fetch price index data for the U.S. For example, the following fails (Mathematica 10.2): ...
0
votes
1answer
83 views

Overriding the behavior of Dot

I would like to override the behavior of Dot, so that Dot[u,v] will return a scalar instead of a 1x1 matrix in the case that the ...
1
vote
0answers
54 views

Odd plotting/math issue (could be a precision problem)

I've got a pretty odd error on a project I'm working on and was hoping to enlist some advice to fix it. The goal of this notebook is to show that I can eliminate the non-normalizable (blowing up part) ...
11
votes
5answers
313 views

Partition a list into sublists of different lengths

I have the list {a, b, c, d, e, f, g, h, i} and I want to make a sub-list of the form {{{a, b}, c}, {{d, e}, f}, {{g, h}, i}} ...
7
votes
0answers
33 views

CountryData vs EntityProperty: why do different data access methods produce different results?

Illustrative example: using CountryData we are told the data is missing, but we can nevertheless access it via an ...
9
votes
1answer
613 views

Can I memoize retroactively?

I have a function defined something like this: f[x_] := Module[...]; I can easily write a memoized version of it like this: ...
4
votes
1answer
101 views

2D Fourier transform

I want to calculate the 2D Fourier transformation of a circular shaped aperture, but Mathematica won't finish the calculation: ...
4
votes
1answer
65 views

Change Notebook's Default Context

In my workflow, when testing/developing packages, It's an common situation to test internal packages functions that has been already loaded with the package, so they are in the ...
1
vote
1answer
83 views

Transformation Matlab assignments to Mathematica expressions

From a simulation software, I obtain in a matlab file my algebro-differential equations in the following way : C_p_e = C_state/C_c; C_p_f = I_state/I_i; R_p_e = R_r*C_p_f; I_p_e = ...
4
votes
1answer
70 views

Two axis on a BarChart

I want to create a BarChart with two different y-axis, one on the left and another one on the right. For that, I did two different ...
0
votes
1answer
31 views

Using NDSolve initial conditions as parameters for a function and then a replacement rule

I am trying to make a function based on two initial conditions of a set of differential equations: ...
7
votes
3answers
301 views

Coloured image transformation in pointillism

I would like to transform an image (a photo for example) into a set of single colour circles with fixed but adjustable diameter (bigger than the pixel size), into a kind of pointillism. The number of ...
9
votes
1answer
156 views

Finding large prime gaps

I am using basic searches for prime gaps as follows: ...
7
votes
1answer
81 views

Is DiscretizeRegion not yet ready ro discretize 3D-solids?

In the DiscretizeRegion documentation: "The region reg can be anything that is ConstantRegionQ and RegionEmbeddingDimension less than or equal to 3." With DiscretizeRegion there could be an easy way ...
6
votes
3answers
119 views

Which values did ImageAdjust choose?

I have a picture obtained from a camera in an experiment. It's a .dat file, contains only numbers. I can re-create the image by importing it as data and using the ...
1
vote
1answer
87 views

How to simplify the equation and speed up the codes for four 100*100 matrices

I have to make a sum over 4 variables. Each variable corresponds to a 100*100 matrix. I want to know how to speed up this code. This problem is related to the previous problem 1 and 2. But now I need ...
0
votes
0answers
60 views

Is tensor argument passing to module expensive?

I wrote a simple module which is supposed to do recursive computation, however it turns out to be expensive even for 300 points. I am not sure why is it slow, all the computations seem to be ...
6
votes
2answers
241 views

Modifying the elements of a list according to a given probability

Let list be a list of lists, the elements of which are random integers in the interval $[1,c]$. Each element $i$ has a probability ...
10
votes
1answer
129 views

“ParametricSensitivity” in ParametricNDSolve

"ParametricSensitivity" is listed as a Method in the documentation for ParametricNDSolve, ...
1
vote
0answers
59 views

Debugging Test files generates exception in Workbench 2 and 3

I'm having trouble running the "test file" example given in the video here http://www.wolfram.com/broadcast/screencasts/workbench/WorkbenchTesterDemo/ in "Debug As...". RUNning the test file ...
0
votes
0answers
39 views

How to plot multiple numeric ODE solutions in phase space [on hold]

I have a system of four coupled ODEs whose solution (and solution process) are sensitive to the value of a parameter $a$. $$\bar X '(t)=\bar F(\bar X, t, a)$$ If possible, I would like to create a ...
1
vote
1answer
61 views

Comparing stock indices using TradingChart [closed]

Below I show a TradingChart specific to the SP500 index for a one month period. How do I produce a similar plot where three other indices (ASX200, Shanghai Comp, ...
12
votes
4answers
167 views

Distributing function arguments with function compositions. How to compute $(f + g^2)(x) = f(x) + g(x)^2$?

Suppose I have two functions f and g. To compute $f + g$ evaluated at a point $x$, I know that one can use ...
4
votes
2answers
104 views

How to plot the ranges of the variables of an iterated integral?

I would like to plot the volume of the following integral: $$\int _{-1}^1\int _0^{\sqrt{1-y^2}}\int _{x^2+y^2}^{\sqrt{x^2+y^2}}\left(xyz\right)dzdxdy$$ Here are the ranges of the variables from this ...
6
votes
2answers
124 views

How to group cell type A under cell type B?

My notebook's groupings for "Subsection" and "SubitemNumbered" are broken: And by broken, I mean I wanted it to automatically group like this which I did manually (with lots of control+shift+g) ...
2
votes
3answers
78 views

Why does Import[#, “ImageLinks”]& fail?

I'm having difficulty with Importing urls embedded in a site (with and without pagination). This command: ...
-1
votes
2answers
51 views
0
votes
0answers
60 views

Error with ND Solve [on hold]

I am new to Mathematica, and I am having some issues solving a homework problem of a differential equation. Here is the code: ...
0
votes
0answers
78 views

Calculating 15 coupled differential equations [on hold]

I have 15 coupled differential equations linear in time that need to be solved. Rewriting the equations in a matrix form, they can be expressed following as a single equation, $\frac{d ...
0
votes
0answers
45 views

How to find multiplication of all elements in a 3d matrix?

Here's my input. It's a 15x4 matrix of 3x3 matrices (In other words a 3d matrix): ...
2
votes
0answers
111 views

Intersecting RegionPlots

Does the Mathematica graphics system have any concept of intersecting regionplots? I've found about intersecting graphics but not regionplots so far. For example, if I want to show the intersection of ...
2
votes
1answer
99 views

Curl expression does not evaluate [closed]

I am using Mathematica 8 on OS X. I am trying to compute the cylindrical curl of a symbolic vector following Mathematica documentation. ...
2
votes
2answers
155 views

Can not generate graph using smooth kernel distribution

I am a newbie to Mathematica so this question might looks silly. I want to generate a smooth kernel distribution graph for this set of data. The data I uploaded has two columns, the first column is ...
-1
votes
0answers
73 views

Trouble summing over many indices [on hold]

I'm trying to solve a problem by using `Sum, but as I have many indices (14) in the summation, the running time is awful. My program looks like this: ...

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