10
votes
1answer
242 views

Is this a bug in NIntegrate?

Fixed in 10.1 Bug is present as of version 10.0.2 checked on windows 7, 64 bit Is this a bug or I missed something? NIntegrate seems to give a different ...
0
votes
1answer
200 views

Finding real roots for an eigth-degree polynomial

The context for this problem is identical to my first question. Unfortunately my previous result for $L$ was inexact since it was a relatively simple approximation. This time I have managed to produce ...
3
votes
1answer
120 views

Pulling powers to the outside of expressions (inverting PowerExpand)

Is there something like an inverse of PowerExpand that pulls powers to the outside of expressions: $$ x^2 y^2 \leadsto (x y)^2 \\ x^2/y^2 \leadsto (x/y)^2 $$ I ...
10
votes
3answers
205 views

Pick with nested list

I have a list of pairs of values. Some of those pairs are invalid based on another list. I would like to select only the valid pairs. ...
1
vote
0answers
51 views

Parameters in NDSolve for an Accurate Graphical Output — What to Tweak?

Friday Greetings, I'm working on an ODE system as a basic model for cancer treatment: $\begin{array}{c} \frac{{dN}}{{dt}} = kN\left( {1 - \frac{N}{\alpha }} \right) - \mu CN\\ \frac{{dC}}{{dt}} = ...
9
votes
2answers
439 views

Mathematica and gaps in continuous plot

I have a bit of trouble with Mathematica and it's plotting stuff. I tried to plot Jacobi amplitude function: JacobiAmplitude[Sqrt[0.1]*x, 10], {x, 0, 50}] but ...
6
votes
1answer
458 views

How can I create a Distribution from its probability density function?

I have a probability density function. Is there a mechanism to create a Distribution object from it, such that normal Mathematica commands that usually work on ...
3
votes
1answer
106 views

Calculating groupwise mean in Mathematica

I have a huge panel data with more than 2.5 million observations and more than 15000 groups. I want to calculate group-wise mean and I also need Id variable in my result. This is what I have done. ...
7
votes
3answers
225 views

Mapping a function over the parts of a deeply nested Array

I have two tensors: tensorS = Array[Subscript[s, #1, #2, #3, #4] &, {2, 16, 16, 19}]; tensorR = Array[Subscript[r, #1, #2, #3] &, {2, 16, 19}]; ...
2
votes
1answer
227 views

NDSolve fails for certain choices of parameters and solve range

I'm trying to solve a pair of coupled ODEs with NDSolve. I know roughly what the solution should look like (both should give periodic functions, pi/2 out of phase, the amplitude of which damp towards ...
15
votes
1answer
265 views

Why won't SparseArray let me store values with the head List?

When you attempt to define a SparseArray with elements that have the head List it complains: ...
12
votes
5answers
802 views

Is there a way to riffle more than two lists?

I thought Riffle would generalize such that Riffle[{a,b,c},{1,2,3},{x,y,z}] would return ...
1
vote
0answers
111 views

Long running time

I gave this data as input: ...
4
votes
2answers
381 views

Set the scale in ColorFunction [duplicate]

The following plot (A) ListLinePlot[{0,1,2,3},ColorFunction->"TemperatureMap"] goes from blue to read. The following plot (B) ...
2
votes
0answers
308 views

Expectation Maximization Algorithm

I would like to use the expectation maximization algorithm within Mathematica. The issue is that I am very basic user and progress slowly with understanding functional programming.. I have found this ...
1
vote
1answer
167 views

Fitting composed model to experimental data

I have mathematical model based on equation: $y(x) = 1 - \sum_{b=1}^{\inf} 2c_b \sin(c_b x/L) \exp(ax) $ (1), where $c_b$ are the positive roots of equation: $c_b \cot c_b + aL = 0$ (2). $L$ is a ...
26
votes
3answers
845 views

Symbolic integration error

fixed in 10.1 (windows) I'm running Mathematica 10.0.0 and encountered a disturbing error in the symbolic integration of a rather simple function ...
2
votes
2answers
186 views

Compose one image over another

I'm a newbie in image processing using Mathematica. I'd like to compose an image $A$ over an image $B$ into an image C such that $\quad C[i,j] = B[i,j]$, if $A[i,j]$ is white $\quad C[i,j] = ...
4
votes
1answer
213 views

Efficient Dyson series implementation

I'm trying to implement a Dyson series \begin{array}{lcl} U(x,x_0) & = & 1 + \int_{x_0}^{x}{dy_1V(y_1)}+\int_{x_0}^x{dy_1\int_{x_0}^{y_1}{dy_2V(y_1)V(y_2)}}+\cdots \\ & &{} + ...
14
votes
4answers
595 views

Find intersecting rectangles groups

I've a list of rectangles in the form {index, {centerX, centerY}, {width, height}} I want to find intersecting rectangles list. I want to obtain a list on the ...
2
votes
1answer
94 views

Faster way to extract partial data from AdjacencyMatrix

I am dealing with a lot of Graph objects. One task is to obtain an Id for each of them. So I first used ...
4
votes
0answers
97 views

Known restrictions for WolframAlpha in CDF Player and PlayerPro

Are there any known (documented?) restrictions for the use of the WolframAlpha function in CDF-Player and PlayerPro? I only found this answer which mentions upper values for various license version, ...
7
votes
1answer
323 views

Why does Mathematica not give simple solutions to simple system of equations with powers

I trt to get Mathematica getting me the simple solutions for x and y from this system of two power equations: $$\text{Eq. 1: } z=x^{m}y^{n}$$ $$\text{Eq. 2: }z=\tau x^{m-1}y^{1-n},$$ The simple ...
6
votes
2answers
240 views

How to understand the process of ListCorrelate when it in two-dimensional condition?

Toady,I learn a function ListCorrelate,and I can understand process of execution his result in one-dimensional. However,the ...
3
votes
2answers
222 views

Get domain for a given function (including e.g. singularities)

I am new to Mathematica and this is probably a simple question, but I can't figure it out at the moment... f[x_]:=1/(x-3) Clearly the vertical asymptote is at ...
2
votes
1answer
94 views

How to obtain a complete list of WordData's “Properties”?

Command WordData["Word", "Properties"] seems to return an endless list of properties, such as: "Definitions", ...
3
votes
0answers
132 views

LogLikelihood function with Multivariate State Space Models

I load the packadge TimeSeries. Depending on the running Mathematica release, one should preliminary remove some built-in function with the same name, e.g.KalmanFilter, I used the following commands: ...
2
votes
2answers
122 views

How to make functions from datasets

I have a csv that encodes the results of plugging certain parameters (say, A and B) into certain functions (say, ...
2
votes
0answers
84 views

Mathematica 10 loads too long time [duplicate]

After starting Mathematica 10 it hangs for about a minute before becoming operational. Internet connectivity is disabled. Start screen is disabled. What should I do? P.S. Opening any help page ...
5
votes
1answer
214 views

Why does Mathematica not simplify this expression?

Consider this simple example: ...
3
votes
1answer
327 views

ContourPlot is slow and unwieldy and generates a large-data graphic

I'm constructing a single contour showing the points in a plane that satisfy a function. The general form is ContourPlot[f[x, y] == 0, {x, 0, .5}, {y, 0.2, .5}] ...
2
votes
1answer
72 views

Manipulating lists with uneven amounts of entries

So I have a list like so list={{a},{b,c},{d,e,f},{g,h}} and the basic logic I want is to be able to manipulate each of the nested lists individually. So If I ...
1
vote
0answers
173 views

Double helices inside an ellipsoidal cavity

This question may be related to a previous query at Plotting a contour on a torus My question is how do you enclose double helix structures (see demonstrations.wolfram.com/DoubleHelix ) inside an ...
4
votes
1answer
153 views

Undocumented overload for Graph?

I stumbled (here, in the expression for the block diagram) upon a version of Graph that I don't see in the documentation over here. That documentation admits three overloads (the following are in my ...
4
votes
2answers
76 views

numerical precision in output file

I want to write the numerical results of a computation to a file which is to be read in Fortran. The data looks like: ...
9
votes
2answers
318 views

Extracting values with multiple keys

I want to extract sorted data from a huge database based upon two (or more) keys in a very timely manner. Here is a reproducible toy example for two keys only: ...
2
votes
1answer
204 views

Numerically solving systems of (first order) linear delay differential equations

I was wondering, how to solve such a system with mathematica? I found the NDsolve function, but in the reference is not mentioned if it is possible to solve a system of equations.
2
votes
1answer
261 views

Find solutions of equation involving Bessel functions

I'm new in Mathematica and I'm trying to find the solutions of this equation involving Bessel functions $$\eta \frac{ J_{n+1}(\eta a)}{J_n(\eta a)}+\chi \frac{ I_{n+1}(\chi a)}{I_n(\chi a)}=0$$ ...
3
votes
1answer
191 views

How to color objects from a single .obj file?

How to paint the dolphin, shark and the box with different colors after loading the .obj file into Mathematica? ...
1
vote
1answer
1k views

Changing the x-axis data range

I have a series of data and Ive ploted them by mathematica.how can I change the x-axis scale?for example instead of "x" being between 0-300, I want to plot my data between 0-2 scale. this is my code: ...
1
vote
0answers
66 views

Make a table of changes in US coinage

I thought of an innovative use of Mathematica/Alpha that I think Stephen Wolfram would really love, but I can't figure out how to get it to work. The idea is to make a table that would chart the ...
5
votes
0answers
263 views

How to draw block diagrams as Graph objects?

In the documentation ClosedLoopResponsesWithAPIDController, There is a very nice block diagram. I want to create my own block diagrams similar to this. I clicked on the diagram and pressed ...
5
votes
1answer
229 views

Dynamic panel crashes Mathematica 10.0.0.0

This answer by @paw have revealed a bug that causes Mathematica v 10.0.0.0 to crash the GUI and kernel. So far the offending code is this: ...
7
votes
2answers
289 views

Get name of hidden inbuilt functions (like Ticks drawing)

how do I get the name and definition of a builtin Mathematica functions? For instance, I would like to see how default Tick plotting function is implemented. However, it is not clear where it is and ...
10
votes
2answers
353 views

How to round tick line ends in the plots

I would like to have rounded ticks in my Mathematica plots. They look much better for thick frames ...
6
votes
1answer
368 views

Using Manipulate to dynamically correct the baseline of a signal

i have data with a baseline and will correct it with a polynomial fit using Manipulate to see immediatly the changes in the resulting spectrum. It works so far, but ...
1
vote
0answers
131 views

Building Reusable Custom Controls?

I would like to build an application using Mathematica 10. I would very much like to structure the application for maximum maintainability. To this end I would like to segregate controls and user ...
5
votes
1answer
199 views

CUDALink Error: A CUDALink kernel timed out?

I'm following the CUDALink tutorial [ http://reference.wolfram.com/language/CUDALink/tutorial/Introduction.html ] and everything is going fine until I get to the part that calls CUDADot on the ...
3
votes
1answer
125 views

Rewrite an expression as a sum of $SU(2)$ characters?

I have an expression of the form $$q^{-3/2} t^{-7/2}[4qt^2(t + q t^2) + t^2 (q + t) (1 + q t (1 + q t))],$$ I can factor it and write it as $4((qt)^{1/2} + (qt)^{-1/2}) + (qt+1 + ...
8
votes
2answers
635 views

Finding the coefficient of a certain power in a generating function

I want to compute $(t^1+\dots +t^5)(t^2+\dots+ t^6)(t^3+\dots +t^9)$ and find the coefficient of $t^{15}$ for example. $t$ is an indeterminate Now in Maple this is simply as ...

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