0
votes
1answer
38 views

Independent test of residuals, absolute member equal zero

Does Mathematica offer any test for confirm independence of residuals? except DurbinWatsonD. And I would like to ask how to make some test in regress function which tests absolute member equal zero. I ...
0
votes
0answers
34 views

Manipulate axis scale on a ListPlot

Use this code to generate my problem ...
1
vote
2answers
69 views

Plot confidence interval around curve

I need to plot a confidence band around a curve in Mathematica, similarly to what done with r in the image below (from here). What is the best way to do it? My ...
1
vote
2answers
154 views

Dynamical system problem x(t+1) = Ax(t)

I have a problem that have been trying to solve but it's not going so good. I would like some guidelines on how to work myself around this problem: Two neighboring countries spy on each other and ...
0
votes
0answers
29 views

Mathematica showing wrong plot for function f(x) = 3/2 +( Sech[1/x]/x)^2? [on hold]

I tried plotting this function for a homework assignment and got some weird result, and putting the same function in to WolframAlpha gave me the correct answer. The function I'm trying to plot is ...
25
votes
2answers
6k views

How to form a block-diagonal Matrix from a list of matrices?

For example, like this: I know join[...] works, but it is a bit troublesome for multiple matrices. I also tried DiagonalMatrix[...], but DiagonalMatrix can only form a matrix from a list of ...
3
votes
1answer
81 views

How to efficiently find only the rational roots of a rational complex polynomial?

I need to find all the rational roots of a bunch of high-order polynomials with rational complex coefficients. Is there an efficient way to do this? My best effort on an example polynomial: ...
0
votes
3answers
74 views

How do I create a circulant matrix? [on hold]

How do I create an $n \times n$ circulant matrix? I couldn't make ToeplitzMatrix do it for me.
9
votes
1answer
399 views

How to make InputTable

There is InputField in mma but how to make InputTable? In MathCAD it`s possible to insert Excel spreadsheet with input and output variables.Input variables I use for filling of header row and column ...
2
votes
2answers
138 views

How can I get LogIntegral[z] to be printed as “li[z]”?

I have no problem with the current formatting of the function, but for the sake of the reader less familiar with Mathematica functions, is there a way to define, say, ...
14
votes
1answer
455 views

How to use 2D Fourier analysis to clean the noise in an image

I have some other method to do this.But I desire to know how to use Fourier analysis to realize it. I found a base post about Fourier-analysis to use in Image-Processing--Calculate the 2D Fourier ...
19
votes
2answers
2k views

What is an “INTERNAL SELF-TEST ERROR”?

I got this all the time after updating to 9.0 (OS 10.8.2): That's Clipboard|c|3015 for the benefit of anyone searching. The error went away with 9.0.1, but a version has reappeared (multiple times ...
3
votes
1answer
42 views

Copy xAct expression to LaTeX

How can I copy an xAct expression to LaTex? Using the usual command TeXForm[] gives the xAct structure, I would like to get the printed form. For example $$ \text{TeXForm}[\nabla_a\phi\nabla^a\phi] ...
5
votes
1answer
66 views

ElementData possible oxidation states

Is there any way to find out the possible oxidation states for a given element? Something like this: ElementData[1, "OxidationStates"] -> {-1, 1} Here is a ...
0
votes
1answer
48 views

CDF Player and CloudObject`Private` Problem

I'm trying to generate a simple Manipulate[] example showing Taylor expansion. However, the following code shows ...
3
votes
2answers
46 views

Numerically solving coupled ODE's with a parameter as initial condition

i'm currently trying to numerically solve a set of coupled ODE's to obtain the functions p(r), h(r) and m(r) in the range of r1 <= r <= r2 with initial conditions m(r1)=a=const and ...
0
votes
1answer
34 views

Why do I not get a result when there is no error message? [on hold]

I've typed in the following equation: Solve[((h*s + l - r*s - r)/(s^2 + s)) (1 + s) - h == (h*s + l - r*s - r)/(s^2 + s) - r, r] and it produces: ...
4
votes
1answer
45 views

Using TraditionalForm to express equations

I have a notebook in which a couple of partial derivatives are calculated. At the time of publishing this notebook, I'd like to make the resulting equations look the way they would in standard ...
1
vote
1answer
22 views

Passive Transformation does not return the expectedt result due to precision of expressions

So I wish to perform a passive rotation in N dimensional space. Let me take N=5 for this question. ...
0
votes
1answer
24 views

Complex number simplifications

My Mathematica notebook is not simplifying some expressions which do look trivial. I mean that one of my outputs contains: ...
2
votes
1answer
125 views

solving Stokes equations for Force=0 boundary condition

Say you want to solve the movement of a particle in a viscous fluid such that the force on the particle is zero. In general, the solution is trivial since one has no-slip boundary conditions, ie the ...
0
votes
0answers
15 views

Théorie de Fourier in Sontag`s book [migrated]

I was reading Sontag`s In America and she mentions: "La théorie de Fourier sur les douze passions radicales.." What is this theorem about?
0
votes
0answers
15 views

ParallelDo does not work, when using variables from other parts of the script

I have a script doing a large amount of calculations with very big matrices that takes so long; so, I want to parallelize pieces of the script to be executed on multiple kernels. For instance, the ...
6
votes
0answers
59 views

benchmark of Mathematica's FEM?

Does anyone have any numbers on how mathematica compares to other commercial (eg ANSYS) or free FEM softwares (eg. FreeFEM++, FEniCS, elmer)? If this is too vague say solving the diffusion equation in ...
14
votes
1answer
3k views

Computation of Hankel Transform using FFT (Fourier)

To address circularly symmetric cases of 2-D Fourier Transformations, the so-called Hankel Transform can be applied (for a detailed derivation of the relation between the 2-D Fourier transform and the ...
16
votes
0answers
161 views

Can Mathematica solve functional equations with nested variable?

First, inline free form input can solve these equations: But it seems no native Mathematica function can solve these, there is even an error page for equations of this form (nestdv). Now my ...
3
votes
1answer
46 views

How can I choose the coeffcients so that the givent system of equations has four integer solutions?

Consider the system of equations with unknown are $(x,y)$. $$\begin{cases} a_1x^2+b_1y^2 + c_1xy+d_1x + e_1y+f_1=0,\\ a_2x^2+b_2y^2 + c_2xy+d_2x + e_2y+f_2=0. \end{cases}$$ I want to find the ...
3
votes
2answers
79 views

Raspberry Pi Temperature and Performance

I just got a raspberry pi 3 and want to get a rough idea of the max temp I might reach while doing intensive calculations. What would you suggest I calculate in mathematica to get the pi hot? ...
1
vote
2answers
35 views

How to round all the numbers in a function?

I have a complicated function that is a combination of floating-point numbers and variables. I want all the numbers rounded off, but I have no clue how to do this. For example I would want ...
0
votes
0answers
20 views

How to attach a notebook to a question? [migrated]

As I have posted a number of times, I am still learning how to do things here. I was wondering if someone could help me to figure out how to attach a notebook file to a question. Thanks Tarynn
0
votes
1answer
45 views

Setting Initial Conditions in a System of Differential Equations that don't start at t=0

I have a system of six differential equations (linear for the sake of the discussion). I want to set the initial condition to start at time t=18 and not time t=0. I know the values of the dependent ...
0
votes
0answers
38 views

Extract stiffness matrix from NDSolve

I am solving a set of ODE equations with NDSolve with more than 25 equations. I was wondering is there any way Mathematica gives me the mass and stiffness matrices?
8
votes
1answer
323 views

Is there a way to make a bihistogram plot?

Is there a way of making a bihistogram plot in mathematica? There is a reference to it at http://mathworld.wolfram.com/Bihistogram.html but no suggestions as to how to do it.
3
votes
0answers
20 views

Text in Popupmenu that cannot be chosen

Is it possible to make a popupmenu where there is text inserted into the options which you cannot choose. For instance: a popup menu with animals devided into two categories. Birds: duck, eagle, ...
19
votes
3answers
3k views

Relative paths for portable notebooks in Mathematica

I cannot find how to use relative paths in Mathematica. My directory structure is simple. ...
2
votes
0answers
213 views

How do I estimate the Pareto front in my multiobjective optimization problem?

I need to minimize a function of two parameters that gives two "stress" outputs {A,B} = f[tau,mu]. How do I estimate (even roughly), the Pareto front for this ...
2
votes
0answers
112 views

Why can't Mathematica solve this equation? [duplicate]

Possible Duplicate: Can Reduce *really* not solve for x here? Why can't Mathematica solve this equation? ...
4
votes
1answer
92 views

Does Solve[] find ALL the exact roots of rational polynomials?

Does Solve[] find ALL the exact roots of rational polynomials? I've done a bunch of tests where I created an expression with some analytic roots, and Solve[] always found them all. But is the ...
1
vote
1answer
106 views

Evaluate pure function through round brackets

In have some matrices of pure functions or numbers which I multiply by other matrices or vectors. I would like the functions to be evaluated in the result, but all that I get is something like this: ...
10
votes
3answers
198 views

How to describe the convex hull of a set of points as an implicit region for optimization?

Last edit: 2016-05-03 A.G.'s answer was the one helped me the most, see explanation at the end of this question. Original question In Mathematica you can create out of a set of points in 2D and 3D ...
3
votes
4answers
161 views

Is there a way to PrependTo or AppendTo while flattening the result in the same step?

arr = {1, 2, 3}; PrependTo[arr, {a, b}] (* {{a, b}, 1, 2, 3} *) But, I want (* {a, b, 1, 2, 3} *) I know I can use ...
0
votes
1answer
18 views

Is it the correct syntax with TransformedDistribution?

I define a function as f[x_] := ...;which is in fact the PDF of a random variable $X$. The PDF if given by $f_X(x)$. Let $Y$ is a random variable, which is the ...
1
vote
1answer
127 views

How can I evaluate a certain probability density function?

The PDF of a random variable $X$ is given by $$f_X(x)=\frac{2m^mx^{2m-1}}{\sqrt{\pi}\Gamma(m)}\sum_{i=1}^{N}W_iH(T_i)$$ with $$H(t)=\exp\left(-m\left(\sqrt{2}\lambda ...
1
vote
1answer
53 views

Create a Dataset object, Association or SparesArray from a matrix [on hold]

I need to make queries and operations on a large dataset. What is the easiest way to add keys to matrix so that it is transformed to a dataset, which can later be used to make queries? Let's take ...
5
votes
0answers
44 views

Macro functions in GeneralUtilities?

Questions have been asked about the Macros package before, but I'm interested if anyone has some examples of using the macro related functions in GeneralUtilities: ...
5
votes
1answer
183 views

Mathematica gravatar engine?

This question asks about making gravatars in Mathematica, but the accepted answer is just a wrapper around the gravatar.com service. Is there an open source Mathematica engine that performs the ...
2
votes
1answer
63 views

Does NDSolve iterate faster in a region where the system being solved is in equilibrium?

I was wondering how exactly the time it takes for NDSolve to iterate through a certain region of the domain depends on the local behaviour of the given system being solved. My guess would be the ...

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