14
votes
2answers
362 views

Can't get Append to append a record (association) to a dataset

The Documentation Center item, Computation with Structured Datasets, implies that Append has been extended in V10 to work with datasets. But not on my computer. (I ...
2
votes
1answer
232 views

GUI of a Karnaugh Map

I intend to implement a three-variables Karnaugh map with the following code. There are two points I failed to figure out. How to remove the outer double-line border? How to change the toggling into ...
7
votes
3answers
708 views

Wrong font selection for some characters in Mathematica 10 for Linux

I've just started using Mathematica 10 on Linux and have immediately run into problems with the fonts. Fonts on Linux are always a headache, but I had managed to find a reasonable one in "Century ...
4
votes
1answer
123 views

1/0 encountered when solving an ODE

What can cause this error to show up? Clear[lambda, a, b, x, y]; ode = lambda y[x] + a b y'[x] + a (-1 + b x) y''[x] + y''''[x] == 0; DSolve[ode, y[x], x] ...
8
votes
1answer
229 views

Expanding derivatives of hypergeometric functions

Sometimes Mathematica expresses results of integration or summation in terms of symbolic derivatives of Hypergeometric2F1 function, and cannot further simplify ...
1
vote
1answer
57 views

Can someone please help me to state assumption?

I am currently trying to solve under what condition does the following term will be zero? ...
11
votes
4answers
279 views

Recognizing special cases of a defined function for permuted arguments

I have a number of ugly ways to implement the following pattern recognition task, but I'm looking for something elegant to keep my notebook tidy. I need to define a function of six variables ...
6
votes
4answers
332 views

Conditional Expectation — How can Mathematica find a more general closed form?

Mathematica can't find a solution to this Expectation. ...
2
votes
1answer
104 views

Finding a root of a parameterized integral

I have a function given as a parameterized definite integral: f[a_] := Integrate[BesselJ[0, x - a] BesselJ[0, x + a], {x, -∞, ∞}] I suspect it has a root near ...
3
votes
4answers
183 views

EventHandler Not Detecting KeyDown

I am trying to use EventHandler to detect KeyDown within a LocatorPane. Anytime I press a key inside the LocatorPane the proper action is not executed (doesn't matter which key I choose) but rather ...
4
votes
2answers
348 views

Conversion of 3D plot to 2D Contour Plot

Is it possible for Mathematica to convert a 3D plot into a 2D contour plot without having to recompute the values for each point? I realize that looking directly down at the 3D plot will be similar to ...
1
vote
2answers
69 views

How does one go from a string to the contents of a variable with the same name?

What command should I use if I want to convert a string to the contents of a variable with the same name as the contents of that string withing a function. ToExpression[] doesn't seem to do it. ...
22
votes
7answers
2k views

Is there a way to recreate the typical Red/Blue-Postereffect using Mathematica?

I think nearly all of us have at least once seen an image like this: So I wondered whether it is possible to recreate this effect using Mathematica because it seems like it wouldn't need that many ...
0
votes
0answers
31 views

Expressions to functions, and evaluation [duplicate]

When calculating derivatives a expression is the result: in:= f[x_,y_]:= 1 + 2 x + 3 x^2 y + 4 x y^2 in:= D[f[x,y],x] out= 2 + 6 x y + 4 y^2 how do i make this ...
7
votes
1answer
324 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 ...
0
votes
0answers
88 views

Problems with NMinimize

I have written some functions that take a matrix and find its minimum inner product with a specific set of vectors ...
0
votes
2answers
114 views

Plot a perfect looking circle using two functions, always look like an ellipse [duplicate]

I want to use the the following two functions to plot a perfect looking circle, but the graph always ends up looking a bit squashed. I've been playing with some of the parameters of the function but ...
2
votes
3answers
780 views

How to use this Lorentzian function fit my data, I tried NonlinearModelFit, it always resulted with an error

The data is uploaded to Ideone http://ideone.com/ktIbVk , my code is : ...
0
votes
1answer
78 views

What is wrong with ContourPlot [duplicate]

Why does this plot have a big blank hole in it? ...
8
votes
7answers
825 views

Populate an upper triangular matrix from a vector of elements

What is the best way to populate an upper triangular (or alternatively: lower triangular or symmetric) matrix from a vector of elements? This example input: ...
3
votes
1answer
138 views

Aborts and beeps without error warning

I have a piece of code that generates a figure, performing a calculation to generate each pixel. At a certain resolution it runs fine, but after a high enough resolution it fails. Mathematica beeps ...
3
votes
2answers
158 views

Retrieving other information on CountryData

The following input will produce some answers, however how do we find out other details, such as the specific year the result corresponds to, as well as the source from which the data is obtained? ...
5
votes
2answers
237 views

Table with multiple iterators running parallel

I want to use Table to generate a list, but it only allows one iterator to increment at a time. So in ...
0
votes
2answers
50 views

Multiply value if it includes a period

I download data from an online source, now I have a problem: the source code doesn't allow to differ between values of 10 (which actually stands for 10) and 10.000 (which is 10'000, but Mathematica ...
5
votes
1answer
378 views
3
votes
3answers
178 views

Multivariate Polynomial Manipulation

I have a large homogenous multivariate polynomial in, say, 5 variables $a,b,c,d,e$. As an example take the polynomial $$a^4+2abcd+a^2 b^2+e^4+cde^2.$$ Now I would like to replace $k$-th power of any ...
3
votes
0answers
68 views

Error solving third order ODE in version 10. No error in V9. DSolve`DSolveKovacicDump`

This is an ode which is solved with no error in V9, but gives a very strange error in V10. Is this a regression bug? On version 9, the ode is solved with no error ...
3
votes
5answers
241 views

Take the next element in a nested list

My problem is the following: Consider a list of elements. To better understanding my following explanations, I would take this example: ...
3
votes
1answer
197 views

Use of Ito's lemma in ItoProcess

In the documentation for the ItoProcess it says: Converting an ItoProcess to standard form automatically makes use of ...
9
votes
1answer
265 views

Connect Frontend to Kernel Started by JVM via JLink

I have a MathKernel started and controlled via JLink from a JVM. The $CommandLine for this kernel is: ...
10
votes
2answers
219 views

Evaluate selection in new window or new notebook?

Sometimes when you have long code you need to check some part of this code. the way I am using currently is to selected the part that I want and then copy it to new notebook and then evaluate it ...
4
votes
4answers
312 views

Automatically growing lists as in MATLAB?

Is there a way to add elements to a list at positions outside the current list's length? Something equivalent to the following MATLAB code snippet: ...
7
votes
1answer
291 views

Porting code from MATLAB

I'd like to switch from MATLAB to Mathematica for my research in digital signal processing. I used Mathematica a lot during the '90s but I haven't used it since then, so I might as well be a complete ...
4
votes
3answers
316 views

How to solve an integral equation by iteration method? [duplicate]

How I can obtain $n^{th}$ approximation of the following equation $f(t)=t+\int_0^tds f(s)$ by iteration method?
4
votes
1answer
164 views

How to input and output partitioned matrices that show partitions and compute as normal?

I want to demonstrate multiplication of partitioned matrices as in the example here. Using the Insert Menu, you can build a matrix and draw lines between rows and columns. However, I want to be able ...
1
vote
0answers
140 views

Solving PDEs with complicated boundary conditions

The system I'm trying to solve is $$\nabla^2 C_{(r,\theta)} =0$$ $$C_{(\infty,\theta)}=C_0$$ $$ [ \frac{\partial C_{(r,\theta)}}{\partial r} \cos(\theta)+\frac{1}{r}\frac{\partial ...
0
votes
3answers
145 views

List of Coefficients of Expression with symbolic Terms

(I am affraid that this is a duplicate, but I read several already asked questions and non of them helped me. If it's already answered, please tell me) I have expressions like this ...
2
votes
0answers
131 views

Mathlink program with low cpu usage on linux machines only

Question I am incorporating some c++ code via Mathlink into my simulations in Mathematica. My questions involves the execution efficiency of the c++ code on different machines. For example, on my ...
2
votes
1answer
88 views

ZTest result not making sense

I'm using version 10. I'm having difficulty with understanding why I'm getting some output from the ZTest function. Here is the code for my specific example. ...
0
votes
2answers
62 views

Eigenvectors inside a maniupulate function

I am trying to make a physics application and it requires that the eigenvectors be taken for a 3x3 matrix. It is my intention that Mathematica never have to deal with the matrices symbolically. ...
2
votes
1answer
91 views

How to efficiently process pasted content from PDF

I had selected a matrix in a PDF file, and paste it onto my MMA notebook. Below is the exact copy-pasted content: ...
3
votes
1answer
187 views

Cellular Automata Neighborhood as Node connections

Can I use the CellularAutomation[] function where the neighborhood is defined by the connections between nodes? For example, if 1 -> 2, 1 -> 3, 1 -> 8, 1 ->1, then the neighborhood of node 1 is the ...
0
votes
0answers
84 views

How can I scale a plot in my Manipulate?

I want use scale in the same way as Mister Trevor Cole in his most excellent demonstration at the Wolfram Demonstrations site: ...
3
votes
1answer
96 views
2
votes
0answers
302 views

Is there a way to use video codecs for avi files in Mathematica?

I would like to use Mathematica to create compressed .avi video files from image sequences. I read the documentation on .avi but couldn't find a solution. In the documentation it says: ...
2
votes
2answers
84 views

Why isn't Refresh working as expected? [duplicate]

This seems to me to be a very easy question, but I can't seem to figure it out. Instead of updating every 1 second, it auto-updates as quickly as possible. ...
4
votes
1answer
92 views

How to create a CDF “on the fly”?

I don't know if I have asked the question the right way: As CDF is essentially a simple text file, I would like to create it "on the fly" without saving it to the hard drive. I would like to give a ...
1
vote
1answer
66 views

A code deal with Lists operation ---Needs optimizion

I have written some code to deal with lists, But the speed of the code is slow, Could Someone help me to speed up it? Probably could rewrite it with Functional Programming! Give me some ideas! The ...
2
votes
0answers
43 views

Custom WindowToolbar for my stylesheet

So I've noticed that some stylesheets (for instance Slideshow stylesheets) load a toolbar using the assignment WindowToolbars -> {"ToolbarName"} and I've been ...
1
vote
0answers
153 views

Numerically solving a 2D oscillating integral

I'm having trouble solving this integral numerically: ...

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