7
votes
3answers
1k views

Determine if solution to linear system exists

I'm trying to determine only if a solution to a linear system of equations exists. I have been using LinearSolve, which works fine, but it solves the system as well....
0
votes
1answer
80 views
14
votes
1answer
433 views

Why is an Identity function needed?

Today I came across the function Identity[x] in Mathematica (documentation). The example given in the documentation uses it in ...
19
votes
2answers
331 views

Where is the old option TraceInternal->True?

Already at least in version 2 (I think), the function Solve calls the function Roots. At that time, I had a rather dirty trick, that still works, to verify this: ...
0
votes
0answers
22 views

Limit Plot range to infinitely thin region [duplicate]

I want to plot a function only in a specific infinitely thin region, like e. g. ...
1
vote
1answer
102 views

How to assert that a list of variables is real in a nice and clean way

You can use the function Element to say e.g. $x,y,z\in\mathbb{R}$ via Element[x | y | z, Reals]. Now if I have a list of ...
2
votes
0answers
143 views

Creating an orrery

I am interested in creating an orrery, ideally with SystemModeler. I have been experimenting with the MultiBody library since that allows you to do animations. The most relevant example seems to be ...
0
votes
1answer
133 views

Help with functions in Mathematica

I'd like to make a function that has many parts. Doing this in something such as Java, which I am familiar with, would be simple. In Mathematica I have these "pieces", which I want to put into a ...
2
votes
2answers
217 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 ...
2
votes
1answer
49 views

How to programatically remove an option for all cells?

I'm trying to remove the CellGroupingRules options in every cell in a notebook. Eventually I opened the Notebook in a text ...
6
votes
3answers
147 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 ...
9
votes
4answers
1k views

Verify Cayley-Hamilton Theorem

Consider the matrix: A = {{-1, -4, -2}, {0, 1, 1}, {-6, -12, 2}} Now, the characteristic polynomial is found: ...
7
votes
3answers
214 views

generating integer partitions

Mathematica can generate integer partitions of an integer $N$. For example, IntegerPartitions[4] quickly gives ...
1
vote
3answers
102 views

Keep leading/trailing zeroes (like Defer except with numbers) in a given number

I'm trying to write a function that counts the number of significant figures a given number has so I can ensure my calculations are rounded correctly; however, I am having a lot of trouble preventing ...
1
vote
0answers
96 views

Is it possible to have more than two vertical axis in Mathematica 2D plots? [duplicate]

Is it possible to have more than two vertical axis in Mathematica 2D plots? This is possible for example in matplotlib (plotting library for Python): http://matplotlib.org/examples/axes_grid/...
0
votes
0answers
116 views

Linear interpolation over 2 variables [duplicate]

I'm tuning a function to data over 4-5 variables using Differential Evolution. The objective function calls frequently interpolation function. I came to a point, where compiling the objective function ...
3
votes
3answers
184 views

How to Plot the PDF of Product of two Normals

I've been looking to plot the distribution of the product of two normally distributed variables, x and y, that are uncorrelated. I've tried symbolically calculating the PDF using the ...
0
votes
1answer
42 views

Manipulating form of output redux [duplicate]

To clarify the question that I posted here, I have the following question: I am generating a very large term by the following: ...
2
votes
1answer
117 views

What Method values are available for Plot?

The Documentation Center article on Plot notes under Details and Options that Method is one of the options for ...
1
vote
1answer
88 views

solving a non trivial equation system

I try to solve a 4 equations, 4 unknowns system. Here is my code ...
4
votes
1answer
137 views

Can I code a conditional jump between cells in a notebook?

How can I code the Mathematica equivalent of the following pseudocode: if[condition] ... goto[label_1] ... else goto[label_2] where ...
4
votes
0answers
236 views

Configuring remote access when using a VPN

To address some of the responsiveness issues, I use the Mathematica front end (v9 or v10) to access a remote kernel on a Raspberry Pi. The (advanced) kernel configuration used is this: Arguments to ...
17
votes
10answers
2k views

Determining the week of a year from a given date

Consider the following: AbsoluteTime["17/04/2012",{"Day","/","Month","Year"}]; From my calendar in my office, I know that April 17th is in the 16th week of the ...
5
votes
0answers
171 views

Finding quasi-cliques

What is the best way to identify quasi-cliques in a graph in Mathematica? I don't think it has been implemented, so are there any solutions to do this? Or do I have to export the graph data somehow ...
7
votes
3answers
175 views
8
votes
1answer
130 views

FindMaximum failing on a trivial problem [closed]

I am trying to solve a trivial optimization problem with FindMaximum but for some reason it is not going. I reduced the problem down to the following non-working ...
0
votes
0answers
34 views

Access interactive web forms [duplicate]

I would like to communicate with interactive web forms, e.g., get the same HTML response as if I had clicked a "select" button and then clicked a "submit" button on a web page. This is for automated ...
1
vote
1answer
82 views

Display coordinates of pointing device in VectorPlot

I want to show the coordinates of the (mouse) pointing device as I move the pointing device over the VectorPlot without a (right or left) click. I have tried ToolTip and MousePosition but I cannot get ...
6
votes
1answer
115 views

Call library function in compile

On the Wolfram official website, there is an example of calling library function in a compiled function: ...
1
vote
2answers
143 views

Are variables always assumed to be real in Jordan Decomposition?

If you give the following input in Mathematica 9.0 (Student Edition): JordanDecomposition /@ ({{1, #}, {#, -1}} & /@ {i, I}) Mathematica gives you two ...
1
vote
1answer
143 views

Mathematica script file in Linux - how to export PDF file and close kernel?

tmp.m file: tmp = Table[RandomReal[], {3}, {4}] Export["test.xlsx", tmp] Quit[] Then ...
17
votes
1answer
342 views

How to determine if a function is continuous?

I wish to write code for Riemann Stieltjes integrals in Mathematica. A necessary condition for the theorem to hold is that the function must be continuous. The domain of the function is a closed ...
3
votes
2answers
721 views

Unexpected result of summation

I wrote a small module that gives me an incorrect output-set. It should be a single number! I don't understand what went wrong. This is the form of summation used: $$\frac{1}{2} (b-a) \sum_{i=1}^n ...
5
votes
1answer
277 views

Fitting a Parametric Curve

I apologize if this question is obvious or simple. I'm in high school and have started playing around with Mathematica only recently. For my Calculus Final, I am supposed to use rotation about the $y$...
2
votes
1answer
161 views

How to convert a rational parametric plane curve into implicit form?

This problem is generated from another Green's theorem related question of mine. And here is a forward of the same problem in math.stackexchange. The original equation of the plane curve is not in ...
12
votes
4answers
5k views

Removing empty sets from lists

If I had a list, say, names= {"Andy", "Bob", "Carly", "Sandy", "Jeff", "Tim", "Tom", "Zach"} and I decide to pick a characteristic only a certain of them have, ...
2
votes
2answers
133 views

How can I create a shortcut for a command in Mathematica?

I am using mathematica to write my physics homework, one thing that trouble me is that I need to enter lots of vectors. I usually type the name of the vector, "A" for example, and then hit "[Ctrl] 7" ...
5
votes
3answers
1k views

Complex conjugate

How do I complex conjugate a vector? ...
17
votes
1answer
789 views

Dual complex integral over implicit path using contour plot

Context I am interested in doing double contour integral over paths which are defined implicitly. For the sake of debugging, let's assume its $$\oint_{\cal C}\oint_{\cal C} \frac{1}{u\, x} d u d x$$ ...
1
vote
2answers
420 views

What's the best way to generate all the upper triangular matrix whose singular values are given?

For example, given $\lambda_1 = 1, \lambda_2 = 2, \lambda_3 = 3$, what's the best way to generate all the upper triangular matrix ($3\times 3$) whose singular values are $\lambda_i$? Note:Given a ...
1
vote
0answers
77 views

Mathematica program for PLUR decomposition of a symbolic matrix using full pivoting

I wanted to ask if there is a Mathematica program for PLUR decomposition of a symbolic matrix M, such that M = P*L*U*R, using FULL (row and column) pivoting, and where R = reduced row echelon form of ...
0
votes
1answer
148 views

Mathematica Lattice Reduce Command

I'm going through a very old copy of "Mathematica: A System for Doing Mathematics by Computer" for self practice. I'm on chapter 3, and ran into the LatticeReduce ...
9
votes
2answers
350 views

$\mathbf L\mathbf D\mathbf L^\top$ Cholesky decomposition

Mathematica can do a Cholesky decomposition $\mathbf A = \mathbf L\mathbf L^\top$, but how do I do a LDL decomposition $\mathbf A = \mathbf L\mathbf D\mathbf L^\top$, with $\mathbf L$ being a unit ...
11
votes
4answers
491 views

Efficient setting of properties of multiple vertices in Graph

The functions SetProperty and PropertyValue can only set a single property of a single vertex, as far as I know. How do I set a ...
3
votes
1answer
60 views
2
votes
1answer
233 views

How can I calculate all irreducible polynomials of 31 degree in $\mathbb Z_2[x]$?

How can I calculate all binary irreducible polynomials of degree 31? or how i calculate all irreducible $f$ in $\mathbb Z_2[x]$? (The irreducible polynomial in $\mathbb Z_2[x]$ and $\mathbb R$ are ...
0
votes
1answer
107 views

How to let Mathematica ignore complex values in Plot functions?

Consider the polar coordinates function of a circle centered at $(2,0)$ with a radius of $\sqrt 2$: $$\rho(\theta)=\left\{\quad \begin{array}{c} 2 \cos \theta +\sqrt{2-4 \sin ^2\theta} \\ 2 \cos \...

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