All Questions

102 views

Why does Mathematica add Hold to the result of my user defined symbol?

In the code below I have defined a symbol that multiplies two block-matrices (I can't use the builtin Dot since Dot assumes that the matrix coefficients commute): ...
70 views

Bug in associated Legendre Polynomials?

Mathematica's definition of the connection of associated Legendre polynomials with $m$ and $-m$ is: $P_l^{-m}=(-1)^m \frac{(l-m)!}{(l+m)!} P_l^m$. We also now that $|m|>l \Rightarrow P_l^m=0$. ...
41 views

Why NMinimize doesn't work [closed]

I have some problem with my code. I need to find root for functional equation F(x)=0, where function F is complex subroutine that uses some external programs for calculation and after all routines ...
31 views

SumConvergence with product $\sum_1^\infty{\frac{1\times3\times5\times…\times(2n-1)}{n!}}$

SumConvergence[( Product[(2 n - 1), {n, 1, infinity}])/n!, n] $$\sum_1^\infty{\frac{1\times3\times5\times...\times(2n-1)}{n!}}$$ However this returns true but it ...
111 views

What is “MouseDragged”?

Maybe I'm picky but I don't consider static pressed button: "dragging". EventHandler[Framed[1], {"MouseDragged" :> (Print@RandomReal[])}] neither does ...
35 views

Coloring specific elements of sets with a prime modified order in an array plot

I have a set of sets: {{1}, {0}, {1, 1}, {0}, {1, 0, 1}, {0}, {1, 1, 1, 1}, {0}, {1, 0, 0, 0, 1}} I’m seeking to apply a color rule to only every other set, starting from the first (from left to ...
114 views

Long running ToElementMesh with very “large” domains

I'm trying to solve a system of PDE over a large domain. This doesn't means I need to have a huge amount of mesh points and mesh elements to discretize the domain. Just that the domains has a big ...
51 views

Correcting a gap in ListPlot

This is a small sample of my data ...
37 views

Coloring all elements in prime ordered sets amongst a set of sets

So I have a set of sets. I want only those sets whose order amongst the sets plus one is prime to be colored (all the same, anything but the standard black). Any ideas? ArrayPlot[{{1}, {1, 1}, {1, 1, ...
69 views

ListPlot3D. Only plots about half of the data in a 3D matrix

Here is the data and the exact command I'm trying to run. I've had success with other datasets generated and written out to a file by the exact same program in the exact same manner but for some ...
51 views

Find the smallest eigenvalue (not absolute value ) for a generalized eigenvalue problem

Related post Find the eigenvector associated with the smallest eigenvalue, not smallest in magnitude I tried to find the smallest eigenvalue for a generalized eigenvalue problem A c= \lambda B c ...
68 views

$L = \lim_{z \rightarrow 1} \frac{1-z}{1-z^*}$ Evaluates incorrectly

I'm about 90% certain this is a Mathematica issue, not me making a silly mistake. I'm trying to evaluate $$L = \lim_{z \rightarrow 1} \frac{1-z}{1-z^*}.$$ Naively entering ...
64 views

CPU usage ~18%, but Mathematica is fully running

I run some very long Mathematica code, and the CPU usage of the kernel is 18% only. Why is not all of the CPU used, can I find the reason easily? Are there known ways to tell Mathematica to use more ...
41 views

Extraneous reaped data with NDSolve and WhenEvent

In exploring What is the range of values $x$ for which $f(x)$ is higher than $k$ over a given domain?, I came across the following strange behavior: ...
68 views

The 1st approximation of multi-viables which contains the differential [closed]

When I input to Mathematica as following, ...
35 views

Defining Solutions to FindRoot a functions of parameters-Part II

Here's a similar question as the the preceding question with the same title, but this time with vectors, which I need to use. I followed the suggestion in the answer the the previous question, but it ...
66 views

Weird behavior when solving a simple physics problem

I have the following code in Mathematica that represents two balls being thrown, one with a velocity v10 (6 in this case) and another ball thrown with a velocity v20 (its just dropped) one second ...
842 views

Can't comment strings with '*)' inside it

I believe it's a bug in notebook's comment parser. I can't comment strings with *) inside it. Something like: ...
39 views

Defining solutions to FindRoot as a function of parameters in Mathematica

This works: f[a_] := x /. FindRoot[x^2 - a == 0, {x, 1}] f[3] (* 1.73205 *) I need this to work, but it doesn't: ...
46 views

Assuming: what am I doing wrong? [duplicate]

Why doesn't this simple line work? Assuming[Element[#, Reals] & /@ {x}, Reduce[x^4 == 1]] (* x==-1||x==-I||x==I||x==1 *) I'm trying to do something a little ...
92 views

KeyMap on a flat Dataset (i.e. Dataset@Association)

How can I go from Dataset[<|"A" -> 1, "B" -> 2, "C" -> 3|>] to ...
47 views

Problem with ParallelTable?

I am trying to numerically solve Bloch equations using Euler's method. My code is the following ...
36 views

Is it possible to generate a message when precision upgrade occur?

I use Mathematica mostly for numerical simulation, so most of the time double precision (or machine precision) is enough for me. Mathematica has this nice feature of automatically upgrade to arbitrary ...
102 views

What is the range of values $x$ for which $f(x)$ is higher than $k$ over a given domain?

What is the easiest way to answer the following question in Mathematica: Given a function $f(x)=y$, what is the range of values $x$ for which $y$ is higher than some number $k$ over the domain of $x$ ...
44 views

Writing rules for Einstein summation

I'm trying to write a list of rules for tensor manipulations and in particular, Einstein summation convention. What I've tried, so far is to write something that would take a generic functions with ...
28 views

ErrorBarFunction styles [duplicate]

I am having trouble making sense of the help I have found for the ErrorBarFunction command. I am looking for basic instructions on how to change the width, style, and color of my error bars. ...
77 views

Why does ToRules return a Sequence?

Why does ToRules return a Sequence expression? Why doesn't it return directly what ...
34 views

Confusing NullSpace Method behaviour

The background of this question is that I'm trying to get the bottom of when the output of NullSpace outputs a list of pairwise orthogonal vectors. On my route to ...
45 views

Why FindMaximum doesn't work in my example

Consider the following function ...
102 views

Custom Grid Lines for ProbabilityScalePlot

I'm plotting up some data using a ProbabilityScalePlot in Mathematica 8. It currently looks like so: Code: ...
49 views

Why does Table returns values but Plot doesn't plot them?

The Table function works fine and return a nice list of values ...
65 views

How to exract the roots from “Roots”? [duplicate]

Given how the output looks like, as in a set of "==" assignments, is it possible to extract specific roots from the output of, http://reference.wolfram.com/language/ref/Roots.html ? And then do a ...
105 views

How do I write nested for-loops?

Looking through the reference.wolfram, I couldn't see an example of how to write a multiple line "for" loop in Mathematica. I need to nest many for-loops in such a way I can do many things in the ...
368 views

Can Mathematica solve Plateau's problem (finding a minimal surface with specified boundary)?

Given a closed curve $\mathcal C$ in three dimensions, is it possible to use Mathematica's built-in functionality to compute a minimal surface whose boundary is $\mathcal C$? For simplicity, let us ...
59 views

Difference Eigenvector values in mathematica 9 and mathematica 10 [duplicate]

I have the following matrix; ...
43 views

Why do I get this error (solving a system of equations)? [closed]

I use the following code ...
36 views

Multi-named Nodes (or Overlapping Nodes) in TreePlot, or Merging Trees

If there is a series of rules from which a TreePlot is made: {D->C, C->B, B->A} And a new node is added that is technically the same as an existing ...
69 views

Simultaneous use of Set AND SetDelayed

Tha Mathematica documentation gives a good example of the simultaneous use of Set and SetDelayed in dynamic programming for the Fibonacci sequence under "neat examples" for SetDelayed ...
34 views

pure functions in nested select

I want to select certain rows from a list by using two nested Select commands ...
21 views

How to use Mathlink mprep to compile external C program [closed]

The reference guide of Mathlink says that a program called mprep takes the template file as input and produces a C file that gives the MathLink interface between your external functions and ...
64 views

Are there methods to serialize and deserialize large calculation runs? [closed]

I have a fairly large calculation to map an electric field over large areas (square kilometers). This runs for a fairly long time. Are there ways to serialize the current state of a running ...
43 views

How to calculate electronic Band structure of cristal [closed]

I need a notebook to calcolate the band structure of a cristal, please can someone help me?
174 views

Drawing all lines between a set of points

Given that I have the array of points, ...
69 views

Initial Value Problem with initial conditions as closed region

Does Mathematica have functionality to solve an Initial Value Problem when the initial conditions consist of a closed region (rectangle) instead of a point? That is, instead of initial conditions as ...
43 views

Exporting A4 size

I have a few tables and graphs that I want to export to a PDF file using Export[....,"PDF"], but I would like to be able to print this PDF-file and still be able to read it. So how can I control the ...
45 views

Generating a list of overlapping end coordinates [duplicate]

I'm a very new user to mathematica so this may be a silly question. i'm trying to evaluate some integral between end coordinates of some evenly spaced range. my range is defined by the number of ...
67 views

How to contourplot a function defined via findroot? [duplicate]

when I use contourplot, the system will simplify the expression first with its parameters holded. However some expressions can not be simplified first without inputting parameters, for example, ...
25 views

Failed to use SetPrecision

I am calculating the below formula:  \text{ER2}(\alpha,\text{K},\text{q})\text{:=}1+\sum _{m=0}^{K-1} \binom{K+\alpha }{m} \sum _{r=0}^m \frac{(-1)^r \binom{m}{r}}{\left(\frac{1}{q}\right)^{\alpha ...