All Questions

6 views

Programming a recursive FFT with Mathematica

I'm trying to program a FFT using a recursive function in Mathematica, though my program is not getting me anywhere at the moment. Could you say what's wrong with it and what I can do to make it work? ...
2 views

Plot sets in the complex plane

I just want to know if there's a way to plot sets in the complex plane. For example $$A=\{z\in \mathbb{C},z+e^{z}=0\},\\A=\{z\in \mathbb{C},\Re(z)+e^{z}\geq0\}.$$
436 views

Mma 10: Half the parallel power (Macs)?

Here is a comparison of the parallel kernels launched under Mathematica under v9 and v10, on the same identical current 2014 R2-D2 Mac Pro ... [ Update: Valerio has commented that the same issue ...
374 views

Parametric regions

I'm trying to plot $a x^2 + b x + c$ where $a, b, c$ (and $x$) take on a range of values. I tried ...
106 views

Numerically solving Helmholtz equation in 2D for arbitrary shapes

I would like to solve the Helmholtz equation with dirichlet boundary conditions in 2 dimensions for an arbitrary shape. (for a qualitative comparison of the eigenstates to periodic orbits in the ...
25 views

How can I export my learned ClassiferFunction[] and PredictorFunction[]s?

Mathematica 10 provides beautiful high-level machine learning functionality. Sadly, the learned functions once created are rather opaque objects. I need to use them in other projects, so here is my ...
24 views

Manipulte is evaluated slowly

I have this function: f[k_, θ_, ϕ_] := Cos[k*Cos[θ]*x + k*Sin[θ]*y - ϕ] I want to change the parameters $\theta, \phi,$ and $k$ to see the effects on the ...
18 views

Why does Rotate in PlotMarkers behave strangely?

While answering Change the inner color of markers I came across a behavior that may be a bug. I would like to know if there is another explanation. First a basic example of normal behavior: ...
25 views

Compare elements in a list

Assume that there are three different points in x-y coordinate like below : p1={4, -1}; p2={5, -2}; p3={1, 5}; In order to compare these points two by two in a ...
12 views

How to make PlotMarkers constructed from Graphics track plot style?

In this plot the Disk[] markers are not colored according to the style of the line to which they belong: ...
336 views

What is wrong with triangle PlotMarkers in v.10.0.0?

In Mathematica 10.0.0 we have built-in graphical triangle PlotMarkers. Let us look closer on them: ...
13 views

Find yards with LWH

I have a box I need to cover all sides with a single layer fiberglass fabric. The dimensions are 34" long; 15" wide; 12" High. How do I determine how many yards I need to buy?
449 views

Change the inner color of markers

I would like to have a marker with white as its inner color, to be able to make this kind of graph: If I use PlotMarkers -> Style["\[FilledSquare]", White], ...
13 views

How to fit data with numerical solution of system of parametric ODE?

I need to find the parameters (k1,k2,k3,k4,k1r,k2r,k3r,k4r) that fit my data (list of [Intensity, time]) using the function ...
25 views

How can I make DensityHistogram obey the lower bound in PlotRange in version 10?

In version 9, DensityHistogram worked with PlotRange as expected: ...
198 views

ToNumberField won't recognize Root as an explicit algebraic number

In Mathematica 9.0.1, it appears that ToNumberField will not always recognize a Root object as an explicit algebraic number. ...
78 views

Why does TraditionalForm[Inactivate[x y]] show x * y ? instead of x y?

Given that both x and y are expressions, in my case x is ...
39 views

Is there a way to check inequalities in Mathematica given restrictions?

Sorry if I'm still a noob, but is there a way to check inequalities in mathematica given some restrictions? For example how could one go about checking whether: Given $a,b,c\in\mathbb{R}$ and ...
58 views

references in a nested matrix

I have a nested matrix n: ...
49 views

ListPlot with conditions

I have a data file containing the position of about $10^5$ stars of a spiral galaxy. Here is the plot and this is the corresponding code ...
145 views

Find intersection points with V10

My question departs from this one: Find intersection of pairs of straight lines but now I want to find the points with the new V10 Region-functions. ...
94 views

Fourier Analysis: How to get rid of a discontinuity

When I compute the phase error of a spatial series data using Fourier analysis in Mathematica there's a discontinuity @ parameter ...
124 views

Apply function to every element of list regardless of depth

I want to apply a function to every element of a list without taking braces into account (depth level), but with the same form of output. Here is an example : ...
49 views

magic rectangle with mma

I was trying to solve this puzzle using mma It looks like the generalization of the magic square. Anyway here my attempt:- There are four columns $(x,y,z,w)$ and nine rowa which are denoted by the ...
144 views

How to generate nonperiodic tilings?

I need to generate nonperiodic tilings which are similar to the attached figure (kite-domino tiling). I was thinking the code is similar to the code for the Penrose tiling. However, that code is too ...
94 views

Why is my compiled code slower?

I am trying to make a Mathematica program run faster. Here is part of the original version. It takes as input the integers X (of order 100), J (of order 10000), and n (of order 100), the real number p ...
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210 views

Given f[1] … f[k], k = 1, 2, 3… how do one find the general function f[n]?

If I have that ...
40 views

3D Contour Plot parts of sphere with gradient less than 0, equal to 0 and more than 0

I want to plot only parts of the sphere of radius 1 where the gradient $\frac{\partial z}{\partial x}$ is < 0, = 0 and > 0. The full sphere is given by: ...
85 views

Probable Bug in HighlightMesh with 2D Convex Hulls created via ConvexHullMesh

One nice way to view the new and exciting Mesh objects introduced in Version 10 is by utilizing the function HighlightMesh, so ...
24 views

Reducing Output length by introducing new variables

I have outputs like "expression/(1+3*c^2) +anotherexpression/(1+3*c^2)" and so on. Is there any way to set 1/(1+3*c^2)=A where A is a new variable so that the output reads like ...
45 views

How to get solution from DSolve

How to get the solution from DSolve in such way that there is no need to copy the result. When for example solving: ...
32 views

How to solve 7 equations with different vars?

a = 0.35; b = 0.4; Delta = 0.1; Q1 = 0.65; Q2= 0.15; Phi= 0.5; Tau =0.28; Rho= 0.01; Mu= 3.7; R = 0.047; A= 0.4; B= 1.99; Sigma = 1.1; e1 := (1 - a) *p*A*K*L^(-a) = (1 - b) B(1-K)*(1 - ...
33 views

specifying a list (vector) of arbitrary length

When trying to do symbolic calculations in mathematica involving a space of dimension n, which is arbitrary but fixed, I'd often like to work with vectors that have ...
27 views

How can Mathematica solve 7 equations and want to find 7 variables [duplicate]

I have 7 equations as below * e1 := (1 - a) p Subscript[A, 0] Subscript[s, K ] ! *SubsuperscriptBox[(s), (L), (-a)] = (1 - b) Subscript[B, 0] (1 - Subscript[s, K]) (1 - Subscript[s, ...
81 views

How to plot stability region of Fourier analysis

Stability limits for Runge–Kutta methods in the complex ΩΔt-plane are needed to be plotted like this: For example, let P=1+z where ...
20 views

DatabaseLink Example for DB2 and Mathematica

could someone please point me to good example on how to make a JDBC connection to an IBM DB2 database?
60 views

ParallelMap returns incorrect results over Map

I've written a function to pull in the useful column of a large data file: ...
40 views

prime-palindromic number selected from a list

I want to find all prime-palindromic numbers up to 5000. Prime-palindromic numbers are numbers that themselves and their reverse digits are both primes. For example, 31 is a prime-palindromic number ...
42 views

Operator syntax for Merge-like Query

Is it possible to take advantage of Dataset's Query operator syntax to Merge parallel queries thereby avoiding Function's that are otherwise required? Using the planets data: ...
68 views

In version 10 EvaluationCompletionAction “ShowTiming” no longer gives useful output; any solutions?

In version 10 using this Front End option no longer gives useful output: SetOptions[\$FrontEnd, EvaluationCompletionAction->"ShowTiming"] In version 7 the time ...
83 views

An argument pattern that my function can treat as Times[constant, variable]

I want to define a function of two variables, func[f_, g_], such that when it sees a general constant multiplying one of the variables, say ...
85 views

How can I graph an equation with five variables?

{c*((a - b*Cot θ)/(Subscript[r, 1])^4) + ((b*Csc θ)/(Subscript[r, 2])^4) This is a form of Poiseuille's Law I need to graph. I want the value of the variables to ...
322 views

Why does Fourier give a shifted frequency?

I have a signal that I want to identify the frequencies in it, I used the Fourier function but I can't get the frequency correctly. Here is a simplified example: ...
37 views

Why does Assuming[…] work in one case but not in another?

Why does this work Assuming[α > 0 && ϵ > 0 && t > 0, FullSimplify @ Integrate[(z^2 Exp[-α t (z^2 + ϵ)])/(z^2 + 1), {z, 0, ∞}]] ...
40 views

NDSolve solution methods issue

I´m modelling a biological reaction thorugh a set of differential equations. ...
110 views

BitShiftRight produces incorrect results in Version 10

With Mathematica 10 for Mac, BitShiftRight works properly on lists of up to 100000 numbers, but appears to give incorrect results when threaded over lists of 100001 ...
1k views

Will Mathematica install and run on Raspberry Pi computer?

My club is considering buying a Raspberry Pi computer for tinkering. Can Mathematica be installed on and ran from it?