1
vote
1answer
35 views

Expand an expression to only built in functions

This question is hard to phrase and even harder to google. Maybe it's best to explain it with a very simple example. ...
0
votes
1answer
27 views

Recurrence evaluation at specific index

I have the following set of equations. I want to solve a[n] and f[n] for the indices n=1:5. Note that the relation a[2n+2] involves the derivative of f[2n] and the relation for f[2n+2] involves the ...
0
votes
0answers
52 views
2
votes
0answers
59 views

Find permutations with constraints without using Permutations

EDIT: To clarify, the bottleneck right now is available RAM, so any answer should keep that in mind (I cannot store all T! lists of length ...
3
votes
2answers
86 views

Finding solutions at non-differentiable points of a numerical function

Let's consider a 2D function we can evaluate numerically, but which is opaque to symbolic manipulation (this is just an example): ...
1
vote
0answers
24 views

Successive addition or deletion of vertices (or edges) in graph

I am trying to perform a kind of dynamic graph simulation where vertices and edges of graph are added and deleted according to the current state of the graph at each time step. I know that there are ...
0
votes
0answers
21 views

PolynomialMod: Unexpected results

Executing PolynomialMod[(X - 1) (X^3 + 2) (X^2 + 1), 2 - 2 X] 0 But ...
0
votes
1answer
36 views

CloudDeploy[FormFunction[ ]] not working

What is wrong with this code: ...
0
votes
0answers
23 views

GeoLabels/Tooltips in Geographic Plots from Dataset

I am looking to plot a list of list of regions, and attach some data to the GeoLabel. All the data is stored right now in a Dataset that contains entries of the form ...
-3
votes
0answers
65 views

Question about ReplaceAll usage [on hold]

I have the following code from the answer of the question (How to impose normalization condition (not initial condition) on DSolve or NDSolve?): ...
7
votes
0answers
81 views

How can I define or use a new coordinate system in Mathematica?

I want to use the dipole coordinate system as defined in this paper: http://arxiv.org/abs/physics/0606044 I see that Mathematica can do all kinds of vector analysis using different kinds of ...
0
votes
0answers
40 views

Why does Mathematica not restrict the domains of Rational Expressions?

As taught in High School Mathematics: $$\begin{array}{ccl} \left\{ {(x-3)(x+3)\over 5(x+3)} : \ x\ne -3 \right\} & \ne & \left\{ {x-3\over 5} : \ x\in\mathbb{R} \right\} \\ \left\{ ...
0
votes
1answer
23 views

WSMModelData[] can not find my model

I have something like this in my notebook (SystemModeler is not running): ...
1
vote
1answer
52 views

Piecewise ColorFunction for Plot3D

I want to make a 3D plot where the ColorFunction is different depending on whether the function value is positive or negative. I know how to do the following: ...
0
votes
0answers
28 views

Need help for Introducing model missmatch [on hold]

I intend do introduce the model mismatch issue from the basic level. The above figure is a very nice example and I found it from a mathematica code which is complicated to explain with simple ...
0
votes
1answer
39 views

Numerical integration of a three dimensional array

I need to integrate a scalar valued function $f\left(\boldsymbol{x}\right)$ where $\boldsymbol{x}$ is a three dimensional position vector; in other words: $\int_{\Omega} f\left(\boldsymbol{x}\right) ...
1
vote
0answers
36 views

Creating Identification/Classification trees

I have data given in following format; from which I need to create identification/classification trees (three different trees from three different criterion, that is average disorder, gain ratio and ...
2
votes
1answer
199 views

Why do the eigenvectors for two similar matrixes differ by a large amount

I have two matrixes with values differs only slightly ...
1
vote
2answers
41 views

function definition with a given list of parameters: how to use Evaluate[] properly?

given a list of variables variables = {a, b, c}; I want to automatically define a function f[{a_,b_,c_},x_] := g[a,b,c,x] ...
0
votes
0answers
59 views

Dynamically update a graphic object in Mathematica

I was trying to simulate a bouncing ball (with no gravity) in a unit box and I managed to come up with a solution: ...
5
votes
1answer
65 views

How to export Speak output?

I made a series of interval workouts based on Speak[], where the voice tells me when the intervals start, when they stop and how much time I have left to prepare. ...
0
votes
0answers
35 views

Automatic measurement of components in a picture

I have a tricky problem, with which I'm stuck just after a few steps. I have the following picture of a slice of the brain. I want to detect all the named structures and measure the area of those ...
0
votes
1answer
55 views

Problem in evaluation of a solution and plotting

I've written out a code which solves a equation and uses this solution to find "ph". ...
4
votes
1answer
87 views

Opacity and Plot

I have the following function : Plot[-2Cos[ Sqrt[50]/2 Sin[theta]] - 2, {theta, 0, Pi/2}, PlotStyle -> Opacity[0.5], AxesLabel -> {θ, E[θ]}] My ...
1
vote
1answer
54 views

Extracting out the Fourier modes of a series, and using these to reconstruct data series

I would like to extract the most important frequency modes from a data set which exhibits strong annual periodicity, as well as some (less) important shorter-term frequency components. The following ...
2
votes
0answers
39 views

Getting error messages from a Plot expression containing an integral [on hold]

This should be a really simple question, but I just got confused. Plot[Integrate[x, x], {x, -5, 5}] Integrate::ilim: Invalid integration variable or limit(s) ...
1
vote
3answers
84 views

I know the lower limit of an integration as well as the integral. How to find the upper limit of the integration?

I used the following code. NV[x1_, x2_] := NIntegrate[3 x^2, {x, x1, x2}] FindRoot[NV[0, t] == 3, {t, .001}, PrecisionGoal -> 20] Output: ...
0
votes
0answers
23 views

Taking a multi-dimensional residue [on hold]

Consider the function ...
7
votes
1answer
206 views

Error in infinite sum

The binary weight of the non negative integer k is defined by w[k_] := Total[IntegerDigits[k, 2]] The first values are (cf. http://oeis.org/ A000120) ...
4
votes
2answers
113 views

Trying to get Arg[1 + I a] -> ArcTan[a]

Can Mathematica evaluate Arg[1+ I a] when a is a positive real in order to get ArcTan[a]? ...
1
vote
0answers
70 views

FullSimplify missing trivial rewrite

I'm trying to understand why Mathematica fails to find the Stirling numbers in the second sum below: ...
0
votes
0answers
40 views

probability - a chess problem [closed]

Question has been moved to http://math.stackexchange.com/questions/1162943/probability-a-chess-problem The question is from: edx -> 6.0.41 -> unit2 -> solved problem -> A chess tournament problem, as ...
0
votes
0answers
56 views

How to control the frequency range of Spectrogram?

How do you control the frequency range of Spectrogram? There is no obvious option. The documentation says it uses the same options as ArrayPlot, but PlotRange does not work in the way expected (it is ...
0
votes
0answers
51 views

Solving coupled integral equations by iteration

I have to solve these coupled integral equations using iteration (all parameters $\in \mathbb{R}$): $f(\alpha,\beta)=f_0(\alpha,\beta)e^{\frac{1}{4\pi i}\int_{-\infty}^{\infty} d\eta ...
0
votes
0answers
18 views

handling the logistics function [closed]

I have the problem, I have to handle the logistics function at two points. That is my initial and final cordenas cordenas. But do not know how to apply that formula. As would be the formula for this ...
2
votes
2answers
168 views

How can I get Histogram to show the number of elements in its bins?

I'm just using Histogram[data, 50]. All the examples on the Histogram help page show show the number of elements when the cursor ...
1
vote
1answer
128 views

Singularity on a simple Plot

While solving quartic equation ...
0
votes
1answer
68 views

Calling C++ from Mathematica Mac OS X

I am trying to call and run the C++ code at the bottom of this post which must be stored in a file called poissonvariate.cpp. I am getting the following error message which I will display here before ...
0
votes
0answers
38 views

Find how many arguments a function has [closed]

I have a function that makes a pure function version of the gradient. It has two inputs, the function and the size of the gradient you want to take. ...
0
votes
1answer
36 views

Import of data from ODS

With SetDirectory["~/Downloads"]; ifile = "test.xls"; TimeConstrained[idata = Import[ifile, {"Data", 1}], 5]; I can achieve the desired result of importing the ...
2
votes
2answers
52 views

Math diacritics go missing when exporting graphics

Take this example plot: plot = Plot[x, {x, -1, 1}, Frame -> True, FrameLabel -> {"x", "\!\(\*OverscriptBox[\(x\), \(_\)]\)"}] When I export it to PDF, ...
0
votes
0answers
77 views

To find a surface with constant Gauss curvature

Please help me use NDSolve to find a surface with constant Gauss curvature $K$ in Cartesian coordinates. I have no previous experience with such differential ...
3
votes
1answer
47 views

Documentation on GeoGridPosition

Wondering where I can find more documentation on GeoGridPosition. Specifically, what formulas does Mathematica use to transform lat/long points to x/y coordinates? ...
-1
votes
1answer
66 views

Help me with sum [closed]

good morning $$ \begin{array}{l} \left\{ \begin{array}{l} u_0 = 1 \\ u_n = 3 - \frac{4}{{1 - v_n }} \\ \end{array} \right.\quad \\ \;v_n = \left( { - 3} \right)^{n + 1} \\ s = v_{1436} ...
6
votes
1answer
150 views

Prevent Export from overwriting files

Export["filepath1",Expression1] works for me, but if filepath1 already exists, it will be overwritten. I'd like ...
0
votes
1answer
49 views

Fourier Transform on a Sound

I don't really know much above Fourier Transform , or how it's used in Mathematica but I want to know how I can find out, out of which Sin-waves a (static) sound is made of. So for example I take "G" ...
-1
votes
0answers
24 views

Iterative Methods for Numerical Solution of Systems of Linear Algebraic Equations [closed]

i want to learn about Iterative Methods for Numerical Solution of Systems of Linear Algebraic Equations. Can you tell me what methods fall into this area? (Jacobiho, Gauss-Seidel, SOR etc........... ...
0
votes
0answers
29 views

Simple Sin plot generates unexpected output? [duplicate]

I an trying to do a very simple smooth Sin wave... Plot[Sin[ 2 Pi 440 t], {t, 0.0, 0.1}] ...but I am getting an unexpectedly non-smooth plot for it... What is ...
0
votes
1answer
40 views

How to speed up ReplaceAll in Table?

I am writing a code which solve a list of equations and then create a Table with resulst of equation solving. In applications where I use this code, I create a bunch of equations and my computations ...
0
votes
1answer
75 views

n-fold convolution

I am trying to calculate n-fold convolution of a function as $G^{*n}(x)$ where $G(x)=1-a*exp(-b)+b*ln(b)$. I tried this function, Convolve[G[x], G[x]^{n - 1}, x, x] but it didn't give any answer. ...

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