0
votes
1answer
77 views

How can I make a graph that compares two sequences

I have two data sets. I produce the first one from the following code: ...
3
votes
2answers
132 views

Multiplication non-deterministic?

I have two vectors of 134 elements each ($mu$, and $gt$). $mu$ contains Integers, and $gt$ contains machine precision Reals. I execute the following simple expression multiple times without changing ...
0
votes
0answers
19 views

How to fix <<MathWorld`Graphs` package cannot be opened? [duplicate]

From http://mathworld.wolfram.com/PaleyGraph.html I downloaded this notebook http://mathworld.wolfram.com/notebooks/GraphTheory/PaleyGraph.nb. The notebook contains the line ...
0
votes
1answer
45 views

How should I compute this triple integral? [closed]

I have tried taking the triple integral of $x \cos(y)$ with the bounds $0<z<1-y, x^2<y<1, -1<x<1$ in the order dz, ...
2
votes
1answer
55 views

AnimationRate not a Manipulate option? [duplicate]

I was trying to set the speed of the Manipulate play button, following this question. Namely, I wanted to specify the option AnimationRate when I have two or more slider controls. However, it seems ...
1
vote
1answer
95 views

Changing Type of Equation To Graph Through User Interface

I'm new to Mathematica. I am trying to create a graph that can change through user interface in more than just the variables. Ideally, I want the user to click a button and have the equation change ...
0
votes
1answer
52 views

Using LinearModelFit, how can I test the hypothesis $\beta=c$ with $c\neq 0$?

Assuming a simple linear model $y=x\beta+u$, is there a way to test the hypothesis $\beta=c$ with $c\neq 0$, using the LinearModelFit?
0
votes
0answers
18 views

Simple heat equation with exponential reaction term [duplicate]

This is the heat equation that i want to solve $${\partial T\over\partial t}={{1\over r^2}{\partial\over \partial r}(r^2{\partial T\over \partial r})+qAC_0exp(-E_a/RT) } \ \ \ 0<t<10, \ \ \ 0<...
0
votes
0answers
64 views

Nonlinear coupled equation (heat equation with source term)

I modeled simple chemical reaction-diffusion equation in spherical region $0\le r\le L$ $${\partial T\over\partial t}={{1\over r^2}{\partial\over \partial r}(r^2{\partial T\over \partial r})+qACexp(-...
1
vote
2answers
69 views

Error In polynomial Root Finding

I have a polynomial in y like so: 2.00855*10^20 + 6.89796*10^20 x y + (5.17347*10^20 + 5.92241*10^20 x^2) y^2 - 1.4806*10^21 x y^3 + 7.77316*10^20 y^4 == 0 I ...
0
votes
2answers
47 views

Part::pspec error occured

I wanted to simulate a noise model on CCD sensors, so I did as below: ...
4
votes
2answers
101 views

How to define action of derivative (D) on a user-defined operator f

I have a symbolic function (which is in fact an operator) f[expr, x] where the second argument is a local variable for f (kind ...
2
votes
1answer
57 views

Disobedient RegionPlot3D

I faced a strange behavior of a RegionPlot3D. I am drawing a piece of a plane bounded by a parabola. This works: ...
0
votes
1answer
87 views

Data Fitting problem

I'm having this kind of data, and I know what possibly the equation is, i suspect this has a sine equation but the plot not really seems sinusoid. so what possibly the equation is so i can do the ...
0
votes
0answers
47 views

Solving a complicated integro-differential equation

I'm trying to solve the integro-differential equation: $-(1+z) H(z) \frac{d f_{i}}{dz} = J_{i}(E',z) - f_{i} \sum_{j} n_{\nu_{j}} \sigma_{ij}(E',z) + \int_{E'}^{\infty}dE~\sum_{j,k}f_{k} n_{\nu_{j}} ...
1
vote
1answer
39 views

How to see Monitor temporary cell with ParallelSubmit?

I have a function to load large files into a "HSQL(Standalone)" database for processing that uses Monitor to update the ...
0
votes
0answers
56 views

How do I interpret an certain expression? [closed]

I used Simplify to simplify some long expression and received pretty long simplified form. A part of the output (in Standard Form) is the following: ...
0
votes
2answers
143 views

Solving equation containing ArcTan terms

IN MY EDIT I DESCRIBE HOW I GOT TO THAT EXPRESSION AND THE ORIGINAL PROBLEM. I have this expression: ...
2
votes
2answers
78 views

Generating a list of file names

I have set of files in the format 20160615-1-0.asc, 20160615-2-0.asc,... 20160615-5-0.asc etc. The following commands can List the file names at once which can be used to import later. ...
2
votes
0answers
45 views

Web crawler: want to ignore login windows [on hold]

I'm trying to make web crawler with Mathematica. ...
0
votes
0answers
56 views

Solve equations involving summation expressions in Mathematica

I am trying to solve the simple linear regression equation analytically in Mathematica (not using builtin functions). I managed to calculate the gradient as follows f is loss function using RSS and ...
3
votes
2answers
190 views

Selection of points based on position

I have a series of points, for example: points = {{0, 0}, {1, 3}, {2.5, 2.5}, {4, 4}, {6, 6}}; I want to join all points successively unless, for example, the y-...
15
votes
0answers
127 views

Any manual on cell grouping management?

Recently I come back to the problem of cell grouping and performed extensive search on this site and on MathGroup archive for information on how to use the possible values of the ...
3
votes
3answers
145 views

Question about Nearest [duplicate]

In the following example Nearest finds the nearest values between list1 and list2 and ...
16
votes
0answers
99 views

Inconsistent handling of Dynamic option values; intended, omission, or bug?

In answering Dynamic ClipPlanes calculated from current ViewPoint Kuba and I got into a brief exchange regarding how Option values wrapped in Dynamic should be ...
1
vote
2answers
107 views

Factor out imaginary unit of root of obviously negative term

Suppose I have the term $t=\sqrt{-a^2-b^2}$, where $a,b\in\mathbb R$. Of course, we know that it holds $$ t = \mathbb i \sqrt{a^2+b^2} $$ which is (in my opinion) more convenient. How can I get ...
-2
votes
0answers
35 views

How to compute a integrate a triple integral? [closed]

I have tried to compute this triple integral but I keep getting an error. I have attached a picture of my code.
1
vote
1answer
124 views

Residue failed to reproduce this residue in a paper

This problem is a more clearly state of my original problem which is off topic, so I reconsider my problem carefully based on previous discussions, and gives the following valid code to reproduce my ...
1
vote
2answers
91 views

Group matrix values by column [closed]

Original Question: I have a list {{a, 1}, {b, 3}, {c, 1}, {d, 2}, {e, 3}}. I want to be able to group the the first number in each pair that has the same second ...
0
votes
1answer
59 views

Why is FindRoot failing to evaluate this function? [closed]

I have a (somewhat long) script which runs cleanly until the very last stage. Here, I'm using FindRoot to attempt to parameterize implicit curves in the zero set ...
2
votes
2answers
364 views

How can I evaluate a certain kind of summation?

I have the following sum P0, P1 and P2 are constants. The problem is to assign all ...
0
votes
1answer
62 views

Error message when running NDSolveValue

I am trying to solve a set of differential equations but keep getting an error. See message below "NDSolveValue::ndnum: Encountered non-numerical value for a derivative at t=0" The system that I ...
0
votes
1answer
56 views

Integral of $(\sin x)^3(\cos x)^3$ [closed]

For the integral of (sin x)^3(cos x)^3 I got 1/6(cos x)^6 - 1/4(cos x)^4 + C. This seemed to work but my book had 1/4(sin x)^4 - 1/6(sin x)^6 + C. This is similar to what I got but instead of cosine ...
2
votes
2answers
124 views

How to plot an Eddington-Finkelstein diagram

I need to plot the same thing as what is shown on the third picture of the site below (sorry, I'm unable to poste that picture here) : http://ion.uwinnipeg.ca/~vincent/4500.6-001/Cosmology/...
-2
votes
0answers
38 views

How to change the default icon of mathematica? [closed]

Is it possible to change the default icon of mathematica to some other picture ?
1
vote
0answers
53 views

Numerically parameterize portion of $F[x,y]==0$

I have a relatively complicated function of two variables F[x,y] whose zero locus contains a number of intersecting paths in the $x,y$-plane. A problem I've been ...
2
votes
0answers
61 views

Why does Expectation function compute, while explicit integration does not?

The code: Expectation[1 + 1/y, {y \[Distributed] ExponentialDistribution[1]}] outputs 1 - EulerGamma While, ...
8
votes
1answer
103 views

Calculating density of states from lists of momentum/energy data

I am trying to calculate the density of states for a 2D system given certain band structure data organized in a specific format. Below is an example of my procedure: Beginning with a simple 2 x 2 ...
2
votes
3answers
128 views

NDSolve and differentiation of Abs

I have found several questions about the derivative of Abs and how it is not defined in the complex plane. What I have not found yet is a precise and simple ...
25
votes
4answers
414 views

$3D$ graphic of soccer ball

How to make a soccer ball $3D$ graphic? The following image is from Wikipedia, Spherical polyhedron: Truncated icosahedron (left) and standard soccer ball (right) ...
6
votes
1answer
90 views

ArrayPlot gives wrong plot legend, how to fix?

Bug introduced in 10.0 and persisting through 10.4.1 My minimal working example is the code ArrayPlot[{{1, 0.1, 0}, {0.1, 0, 0}}, PlotLegends -> Automatic] ...
0
votes
1answer
41 views

Issues with Functions Defined as Eigenvalues [on hold]

I have to calculate eigenvalues of 4 different matrices. The code I'm using is below, but essentially three out of the four are working with no problem, and one (the eigenvalues I've defined as y) ...
2
votes
1answer
98 views

Speeding iterative computation

I want to get the following iterative sequence ...
0
votes
0answers
5 views

How to derive a Taylor series from the ones we know (cosx, sinx, …) [migrated]

If we know the Taylor expansion for the cos(x) function around 0, how can we use it to derive the Taylor expansion of a similar function (cos(x+π/4)) around 0? I do know how to get the Taylor series ...
1
vote
2answers
53 views

How to use quantities obtained by solving equations directly to plot

I want to know how we could use the quantities we found by solving simultaneous equations, directly into plotting graphs. For example I have this Mathematica code; it gives the values of ...
3
votes
1answer
180 views

Alternatives to For/Do Loop to optimize indexing Matrix

I am trying to optimize my code that searches for elements in the rows of matrix that are greater than 0. Then use that position to grab the element from other matrix. I use the do loop to iterate ...
0
votes
0answers
15 views

No MenuBar despite CurrentValue[EvaluationNotebook[],WindowElements] saying it exists

I have 32-bit linux 14.04 (arch returns i686) with Mathematica 10 {$Version in Mathematica ...
0
votes
0answers
49 views

Symbolic series

Mathematica realises, of course, how to deal with symbolic series: Sum[g[x]^k, {k, 0, ∞}] (*Out: 1/(1 - g[x]) *) I.e. it does not worry about values of ...
0
votes
0answers
59 views

Are the following implemented: Differentiable, Continuous, Interior Point? [closed]

FunctionDomain is a great Mathematica function. It tells you the natural domain of an expression. Has anyone (or is anyone) working on a similar thing for checking ...

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