# All Questions

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 ...
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 ...
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 ...
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] ...
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 ...
57 views

I am currently trying to solve under what condition does the following term will be zero? ...
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 ...
332 views

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

Mathematica can't find a solution to this Expectation. ...
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 ...
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 ...
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 ...
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. ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 : ...
78 views

### What is wrong with ContourPlot [duplicate]

Why does this plot have a big blank hole in it? ...
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: ...
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 ...
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? ...
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 ...
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 ...
378 views

### Mathematica 10 fails to calculate integral that Mathematica 9 can handle

The following: ...
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 ...
68 views

### Error solving third order ODE in version 10. No error in V9. DSolveDSolveKovacicDump

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 ...
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: ...
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 ...
265 views

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 ...
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 ...
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. ...
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. ...
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: ...
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 ...
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: ...
96 views

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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: ...
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. ...
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 ...
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 ...