4
votes
3answers
297 views

How to correctly project heat map onto map

I'm importing the NGA ASAM piracy database into Mathematica for analysis. ...
4
votes
3answers
92 views

Question about Replacements and String Manipulations

I'm trying to get better at Mathematica and in the book I'm using (by Nancy Blachman) is the following question (which apparently was taken from another book: The Art and Science of C) which reads: ...
2
votes
2answers
127 views

Problem setting up C compiler on a Mac

This is a follow up to this question. I am using Mma 10 on a MacBook-Pro with OS-X Mavericks. After reading the documentation under CCompilerDriver/tutorial/SpecificCompilers I did the following: ...
6
votes
2answers
201 views

Why does Mathematica appear to change the head of certain expressions?

I don't know if the question trivial or not (if so I will delete it), but here is what I have: I know that x x (* x^2 *) Looking at the full form gives ...
2
votes
1answer
103 views

Minimizing a function with some restrictions

I need help in finding a way to minimize a function with some complex constraints. I'm not an expert in this field, but I'm still trying to understand if I can do something with my problem. So, ...
1
vote
2answers
139 views

Higher derivative [closed]

Is there more efficient way to rewrite this code in order to compute 2nd and higher derivatives of r=sqr{x^2+y^2+(z-a)^2}? ...
1
vote
2answers
63 views

How do I format expressions so that replacement rules correctly apply to exponents? [duplicate]

I have a series of rules that I would like to apply to a series of expressions with variables, but cannot get Mathematica to correctly recognize that these rules should apply when my variables have ...
1
vote
0answers
59 views

Internal self-test error MLParseStream|c|297

I have been plotting time-dependent vectors. Earlier I used the following plotting options: ...
4
votes
1answer
258 views

How to clean up messy data

The start of my question is about one specific situation - I have some erroneous lat/long values in a dataset which I need to clean up. But I'd like it to cover the overall topic of cleaning up messy ...
0
votes
1answer
90 views

Series expansion for $\frac{1}{x+1}$ in terms of $\frac{1}{x-1}$

I would like to expand a function as $$\frac{1}{x+1} = \frac{1}{x-1+2} = \frac{1}{x-1} \frac{1}{ 1+\frac{2}{x-1}} = \frac{1}{x-1} \left[ 1- \frac{2}{x-1} + \left(\frac{2}{x-1}\right)^2 + \cdots ...
1
vote
2answers
93 views

How do get an output table or a plot of individual variables from NDSolve output

I have the following equations and settings: ...
7
votes
3answers
160 views

Substituting values in 3j symbols

I believe these three expressions should give the same answer of -1/Sqrt[3], but the first gives +1/Sqrt[3] whereas the second ...
10
votes
8answers
432 views

Forming an upper triangular matrix from the elements of a list

I asked this question before, but i was closed because it the question was not comprehensible enough. So i reworded it, hope that's ok. I have a list with 6 elements. ...
0
votes
0answers
82 views

how to solve an optimization problem in terms of matrices as the argument

How can I minimize an expression of the form a^T A a where a is a matrix. The following approach does not work if ...
0
votes
1answer
52 views

Using ImplicitRegion to define an ellipse around Multinormal distribution for integration

I have both a 2D 'MultinormalDistribution', and also a single xy point, and I would like to be able to calculate the probability of this point (given the multinormal distribution) and also plot an ...
5
votes
1answer
106 views

Series expansion for $\frac{x}{1- \frac{1}{x}}$

I would like to expand $\frac{x}{1- \frac{1}{x}}$ as $$\frac{x}{1- \frac{1}{x}} = x \left( 1+ \frac{1}{x} + \frac{1}{x^2} +\frac{1}{x^3} + \cdots \right) = x + 1 + \frac{1}{x} + \frac{1}{x^2} + ...
1
vote
1answer
102 views

Manual maximum likelihood estimation of a mixture with no closed form

Let $X$ be a random variable that is from a mixture of two Lognormals (Lognormals(mu1,sigma) and Lognormals(mu2,sigma)) and set $Y=X_1+X_2+...+X_{10}$ a sum of 10 random variables from this mixture. ...
8
votes
2answers
231 views

Unexpected behavior when using SortBy as a dataset filter

I am still experimenting with datasets. Recently I tried to query the Titanic example to get info on the oldest passengers. Here is what I tried ...
3
votes
1answer
63 views

Is it possible to change the fontsize when printing a notebook in the working enviroment?

I want to print a notebook that owns syntax color,I use the Szabolcs's method SetOptions[$FrontEndSession, PrintingStyleEnvironment -> "Working"] Then I can ...
7
votes
1answer
115 views

User-defined DistanceFunction for RegionNearest

In the function Nearest , I can define my custom function using the DistanceFunction option. e.g: ...
1
vote
0answers
83 views

Displaying subscripted symbols with TraditionalForm

I have pasted this code in from Mathematica 10 ...
6
votes
2answers
102 views

How to name a variable with the value of another variable?

A simple but very important (at least for me) question. In some languages for defining a variable, for example, we can do: i=10 "d"&i=30 So I have defined the variable d10, and... d10=30 ...
11
votes
5answers
305 views

How to prevent function from passing values to slot

For the following example: {#, #} & /@ {1, 2} I am trying to find a method to hold one of the slots (or both ) so that the function do not pass the values to ...
2
votes
1answer
111 views

Graphic using manipulate runs too slow

Here is a naive coding of a projection of a point on a sphere. It runs very slow. Can it be changed to run faster without losing its essential analytic character? ...
1
vote
2answers
38 views

how to extract a matrix and a vector from a vector [duplicate]

I have a vector like this: V = {a*exp1+b*exp2+c*exp3, a*exp4+b*exp5+c*exp6, a*exp7+b*exp8+c*exp9} and I want to get : ...
4
votes
1answer
289 views

Use of Strassen's algorithm

Strassen's algorithm is an algorithm for matrix multiplication that is asymptotically faster than the naive one. In practice, the matrices involved have to be quite large before Strassen's algorithm ...
4
votes
0answers
98 views

Precision problem while evaluating RegionMember or Element in V10

I'll try to give you a background on where the problem occured. The problem itself is defined near the end of the post. I'm running a sort of a simulation of a particle in a box. I finally got my ...
3
votes
1answer
120 views

How can I efficiently ArrayFlatten a matrix of sparse matrices?

I have a matrix of sparse matrices that I want to convert to a sparse block matrix. So, basically I want what ArrayFlatten does, except that I want the output to be ...
4
votes
2answers
112 views

How do I make my function behave more like Plot? [duplicate]

I have written a function Fun as below: ...
1
vote
1answer
79 views

How to solve the warning problem and obtain real roots without imaginary part?

I am trying to solve a equation with Newton's method via FindRoot, and the codes are: Define the functions: ...
3
votes
1answer
180 views

How to smoothly change the radius of a circle by dragging its circumference?

I am attempting to set an EventHandler to change the radius of a circle by dragging on its circumference. But the response to the dragging is terribly slow. What is ...
1
vote
3answers
228 views

Finding maximum value with position from Table of values

I have this table of values, how do I find the maximum value? i.e. find $z_{max}(x,y)$ ...
1
vote
2answers
123 views

How to draw a line (1D) with labeled subdivisions

I want to draw a simple line with some symbols, but so far have had no luck finding an easy way to do it in Mathematica. Does anyone know if Mathematica can easily implement e.g. the example below?
7
votes
0answers
218 views

Dataset: cannot reproduce a basic example. A bug?

Just to report: I try to reproduce the very first example for the Dataset from the Documentation Center: ...
0
votes
1answer
76 views

Probability of xy point on bivariate normal distribution [closed]

I have a bivariate normal distribution and I am trying to calculate the probability of finding a point at a certain distance from the mean, so far with limited success. My approach has been to build ...
0
votes
1answer
68 views

Solving minimum length confidence interval problem

I'm trying to find the minimum length of a confidence interval for the variance from a sample iid with normal distribution. I tried ...
2
votes
1answer
312 views

Mean squared error of two matrices [closed]

I want to compare two matrices. For this I use the mean squared error between them with the following code mse[mat1_, mat2_] :=(mat1 - mat2)^2 // Flatten // Mean ...
5
votes
1answer
211 views

How can one compute a 3D Periodic Delaunay Triangulation using DelaunayMesh?

Given a non-periodic point set, one can easily tetrahedralize it using the new (in V10) DelaunayMesh function. e.g.: ...
1
vote
2answers
82 views

extract x and y axis from plot

I am trying to write a function that read what is the FrameLabel of a plot and translates that to filesystem friendly name, that, for instance does not contain "/" or greek characters and so on ... ...
5
votes
2answers
283 views

How to draw a box with holes using Mathematica

How to draw these two(especially the second one) graphs using Mathematica? The curve is not important.The point is how to dig some holes in a cube. BTW, These two shapes are Homotopy.
1
vote
1answer
58 views

How to get only the real solutions of an equation? [closed]

Is there any simple way to get only the real solutions of the eq. x^3-1=x? I've tried: Solve[x^3-1==x,x] But it gives the complex ones, too. I have Mathematica ...
1
vote
1answer
56 views

How to Solve a Sequence in Mathematica [duplicate]

Given the input and the output, how do you interpolate a function in Mathematica? For example if you know that $f(1)=\frac{1}{2}$, $f(2)=\frac{1}{3}$, $f(3)=\frac{1}{4}$,... how would you solve for ...
2
votes
1answer
229 views

How to determine Fixed Point of a function? [closed]

A function is defined as f[x_]=Sqrt[1-x^2]. How can I determine the fixed point of f? I've tried this: ...
20
votes
1answer
462 views

Convex optimization

I am playing with some Compressed Sensing (think single pixel camera) applications and would like to have a Mathematica equivalent of a Matlab package call Convex Optimization (CVX). Specifically, I ...
5
votes
2answers
119 views

How can I save a Manipulate's control settings to a dataset?

This is probably an extremely simple question. I have a manipulate that sets variables used to define an offset, amplitude, frequency and phase of a trigonometric function. ...
4
votes
2answers
118 views

Faster Alternative to DeleteDuplicates for deleting elements in list [duplicate]

I have a list in this style data={{a1,b1,c1,d1,e1,f1}, {a2,b2,c2,d2,e2,f2}} I need to delete all elements in which b1 is ...
11
votes
12answers
577 views

How to group each element with each consecutive elements in one head

Suppose I have the following list: list = {a, b, c, d} I want to generate this result: ...
1
vote
1answer
202 views

Trying to access Twitter returns Cannot import data as JSON

I am trying to use the Social features of Mathematica 10. The Facebook interaction works, but with Twitter I am getting "Cannot import data as JSON". Example: ...
1
vote
1answer
100 views

Plot sets in the complex plane [duplicate]

I just want to know if there's a way to plot sets in the complex plane. For example $$A=\{z\in \mathbb{C},z+e^{z}=0\},\\A=\{z\in \mathbb{C},\Re(z)+e^{z}\geq0\}.$$
1
vote
1answer
177 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? ...

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