3
votes
1answer
622 views

Why this numerical integration takes so long?

Let me explain the problem. I am trying to integrate a one dimensional integral: $$\int {g\left( {{k_x}},parameter1,parameter2,...\right)d{\mkern 1mu} {k_x}} $$ for the sake of clarity, I will give ...
42
votes
1answer
1k views

How can I manipulate TemporalData?

Version 9 introduced TemporalData but, truth be told, the documentation doesn't suggest that one can do much with it. Many of us have probably assumed we'd be ...
0
votes
2answers
216 views

Solving Within InverseCDF

I have the following input data: Remove["Global`*"] x = 5/30 // N; y = 0.8; μ = 0.2; T = 5; ρ = 0.8; σ (*to be determined*) And this is the given equation: ...
0
votes
1answer
298 views

FindFit: why do I get negative value as result?

I am trying fo fit a model to data using FindFit. ...
0
votes
0answers
542 views

Metric Parameters such as Pratt Figure of Merit (Pratt-FOM) for Edge Detection

I have developed a new algorithm in Mathematica v9.0 for the Edge Detection and want to compare it with the existing Roberts, Sobel, Prewitt etc, operators in the presence of Noise. I have evaluated ...
7
votes
3answers
2k views

Simulate MATLAB's meshgrid function

Here is MATLAB's meshgrid. I came up with these implementations in Mathematica: ...
1
vote
1answer
469 views

How to compute the Multifractal Spectrum of a Financial Series with WTMM

I would like to know if someone knows how to compute the Multifractal Spectrum of a Financial Time Series (Currency) througth the Wavelet Transformation Modulus Maxima (WTMM). I would highly ...
5
votes
2answers
233 views

Automate mouse clicks with Mathematica

I need to automate mouse clicks with Mathematica. However, a similiar question was closed on this forum, without any answer. Consider the following steps: ...
1
vote
0answers
383 views

NDSolve for a large system of coupled (complex valued) ODEs

The system under consideration here is a generalization of the one I discussed in this problem. Qualitatively, I am trying to solve a system of coupled nonlinear (up to order 4 in the dep variables) ...
1
vote
2answers
314 views

How do I create matrices with arbitrary list restrictions?

I want to randomly generate a square matrix of dimension n with entries in the list StartingEntries, and also satisfying that for any such matrix M, the matrix Inverse[IdentityMatrix[n] - M] has ...
6
votes
1answer
266 views

Programmatic generation of enhanced (Enterprise) CDF

How does one PROGRAMATICALLY generate enhanced CDFs under an Enterprise license? Undocumented options to CDFDeploy[] perhaps?. Wizard works fine for me, but attempts to do this programatically (from ...
1
vote
2answers
437 views

Draw the image of a complex region

I'm working on a complex question that asks that I determine a function that maps the complement of the region $D=\{z:|z+1|\le 1\}\cup\{z: |z-1|\le 1\}$ onto the upper half plane. That is, $f$ must ...
8
votes
3answers
202 views

Preserve information in flattening a nested list

I have a series of lists in the form below: list={ {1,1} , {2,2}, {3,{3,1},{3,2},{31,{31,1},{32,2}}} } Its a nested list which the dimension is changing case to ...
2
votes
2answers
195 views

Time differences between code using user-defined probability distribution and code using built-in distribution

Why is the reponse time of of kernel significantly different when I use the first code rather than the second? Shouldn it not be the same? Is there any way that the response time can be made smaller ...
0
votes
1answer
81 views

Scope of expression in a user-defined function

I have the following code: fbasic = A + R + Z*Z *Z*Z; f[A_, Z_, R_] := fbasic + R; f[0, 2, 3] The answer I am getting is ...
9
votes
1answer
97 views

IntegerDigits has Listable attributes, but not fast

See this example, a function has Listable attributes often more efficient than Map,but why is this one is an exception? ...
4
votes
4answers
276 views

Elegant Matrix Combinations

Suppose you have a matrix (mxn), simplified for illustration m= {{a, b, c}, {d, e, f}} And a set of combinations (simplified for illustration purposes but can ...
0
votes
1answer
214 views

How to compute values only if input fields are filled?

In the following code how can I keep the DynamicModule from computing values if the input values are not all filled? If I don't specify default values it will show the code used to compute the values ...
3
votes
1answer
61 views

Button ImageSize x-dimension ignored

How can a small square button be created with ImageSize -> {20,20}? The x-dimension won't go below about 70. (Using version 9.0.1 on OS X.) ...
6
votes
1answer
347 views

Changing a wave simulation

I want to adjust some code that I found on this Wolfram Demonstration: http://demonstrations.wolfram.com/WaterRipplesPassingThroughASlit/ Basically it shows a wave passing through a single slit. I ...
0
votes
2answers
177 views

Compute percentages in a list

I have a data file which contains thousands of lines and each line has eight elements. Here is a small sample of the data file ...
-2
votes
2answers
243 views

Mathematica not assigning variable correctly

So I have been fiddling with this the last hour and I just can't get it to work. I have 3 matrices of the same size which contain nothing but 0's in a list, I also have 3 matrices of the same size ...
18
votes
6answers
1k views

Looking for a way to insert multiple elements into multiple positions simultaneously in a list

I would like to take the following data: insertvalues = {r, x}; insertpositions = {{1}, {5}}; origlist = {a, b, c, d, e, f, g}; and generate output that looks ...
0
votes
1answer
499 views

Reassign Functions for Graphic Representation [closed]

How might I construct a function of the form Rep[defs,code], graphic[code] and display[code] ...
6
votes
1answer
859 views

Clear and Unset doesn't free memory

Example: Try this example only if you have > 4G ram d = 2000; f[x_, y_, d_] = Sum[Subscript[a, i, j]*x^i*y^j, {i, 0, d - 1}, {j, 0, d - i}]; Then ...
7
votes
3answers
481 views

Identifying when two graphic objects overlap

I'm designing a small demonstration that helps to visualize the reason behind shaping an electrode that is used to probe a surface: ...
5
votes
1answer
580 views

Packing squares into a circle

I am currently trying to solve and understand a problem about packing the maximum of squares into a circle. What I am trying to do, is to calculate the maximum number of variable sized squares (with ...
1
vote
1answer
506 views

NSolve cannot solve system of equations in Mathematica

I have the following two equations: ...
1
vote
1answer
204 views

ListPlot under conditions Part II

I have a data file containing several columns and thousands lines of data. Below I present a small portion of it, in order to express my issue: ...
4
votes
4answers
289 views

Generate Non-Singular Matrix of $n*n$ dimension

I want to create a function that will make an $n*n$ matrix which is non-singular that will always retrieve the same matrix (meaning that the matrix will not be random each time). I tried using the ...
2
votes
1answer
335 views

How to get the coefficient list

polynomial=-x^4+2 b x^3+(b^2-c^2+2 c) x^2+(2 b c-2 c d) x+c^2-d^2 This is good CoefficientList[polynomial, x] But how to ...
0
votes
0answers
84 views

RSolve and “the given boundary conditions lead to an empty solution”

I am trying to solve the following recurrence relation: ...
12
votes
5answers
573 views

Filtering elements from a list that appear only once

I want to be able to select elements from a list that only appear once. I originally had this: Select[Table[Count[list, i], {i, list}], # == 1] But the issue is ...
13
votes
1answer
770 views

ListSurfacePlot3D generates ugly artifacts

I have a list of $\{x,y,z\}$ pairs representing points in $R^3$. For every unique value of $z$ there are many $\{x,y\}$ pairs defining a polygon/contour in that particular $z$-plane. My dataset looks ...
16
votes
2answers
596 views

Paste data into Mathematica with formatting

Select the following Mathematica code and paste it into a notebook. In Windows 7(Mathematica 8) the line breaks are not interpreted in the expression. In fact any data copipasted from stackexchange ...
2
votes
1answer
197 views

Match a sequence of integers

I would to match a pattern p1 = 0,0,1,0,0 to the elements in listA. The elements are a boolean sequence that may look like this ...
40
votes
3answers
498 views

What bug fixes can be implemented in init.m?

In comments on this question, Mr. Wizard suggested a community wiki to share the bug fixes/workarounds (or possibly other tricks) people load in their init.m. I ...
0
votes
0answers
32 views

Asynchronous evaluation of a button's action [duplicate]

What would be the best way to have the value of x update before the pause (or a similarly slow function) finishes executing? ...
7
votes
2answers
267 views

Using MatchQ (or other means) to parse an expression using sums of COS or SIN correctly

I am writing a function that will take an expression as input. I want to make sure the expression is valid first before processing it. Looking for a correct to use ...
0
votes
1answer
185 views

Defining functions with changing number of variables [duplicate]

I am working with a bunch of functions of the form fn[x1_,x2_,x3_,...,xn_] := x1x2+x2x3+...+xnx1 where $n$ changes. Is there a way to create these functions ...
8
votes
0answers
887 views

Resources on Mathematica and strong AI (a.k.a. AGI)

David Deutsch (physicist / quantum computing theorist) wrote an article for Aeon Magazine last year: On Artificial Intelligence that got me thinking. The article assesses and critiques the ...
6
votes
1answer
97 views

Error when putting ??symbol in a cell with another expression

Putting ??symbol in a cell and another expression in a different row of the cell returns the following error: ??symbol 1 + 2 ...
4
votes
4answers
229 views

How to avoid writing $K$ loops?

I want to evaluate a mathematical function of $K$ variables each of variables varying between 1:N. One way to do this is writing $K$ loops and varying variables accordingly, as shown below: ...
1
vote
1answer
190 views

Error when using FullForm with ?symbol

Information[symbol] shows information about a symbol and is equivalent to ?symbol. ...
2
votes
1answer
119 views

What is the best way to produce a symmetric semi-definite matrix using as few variables as possible?

As we know, there are only $\frac{n(n+1)}{2}$ variables in a symmetric $n$-dimensional semi-definite matrix. Is it possible to produce a $n$-dimensional semi-definite matrix whose trace is $1$ using ...
1
vote
2answers
334 views

Error using Solve on Matrix Multiplication

I am trying to make a function the will find that value of $x$ in the following equation: $x.a=b$ all values of $x, a, b$ are matrices. The dimensions of $x$ are unknown, but $a$ and $b$ have the ...
6
votes
2answers
2k views

Solving a stochastic differential equation

How do I solve the following simple stochastic differential equation: $$ m x''[t] + \Gamma x'[t] + k x[t] = \sqrt[]{2 k_{b} T/\Gamma)} \eta[t] $$ here $\eta[t]$ is Brownian motion, i.e. Wiener ...
4
votes
4answers
947 views

How to show multiple images with a for loop

I wrote a simple application(I put the code in the end) to detect the parallel line pairs in the following picture: It returned three pairs of parallel line: ...
1
vote
1answer
171 views

Find size of vertex image relative to the graph coordinate system

I am trying to define a graph using my own VertexShapeFunction with an ActionMenu button being the vertex and a custom ...
7
votes
1answer
185 views

Why does Mathematica not simplify the Gudermannian function?

The Gudermannian function is built into Mathematica, but does not reduce to simpler terms in some simple cases. In particular, the Gudermannian is an odd function of real arguments but Mathematica ...

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