# All Questions

33 views

### Select elements of a Matrix that are the same (or have certain relationship) and return their position and the element itself

I have a matrix and I want to pick the elements that are the same and return their positions and their values. It seems easy to me, but all I know is how to pick elements that satisfy certain ...
14 views

Thats my problem. I'm trying to upload some code in the correct format for the site and I get: "Error parsing source notebook". The Manipulate cell of the file ...
26 views

### Any ideas on how to use the Region context?

If you type ?Region* you'll get: which seems a bunch of interesting and not documented symbols. Any idea (or experience) on how to use them?
22 views

### How to enter and solve this equation in finite fields?

Is there a way in Mathematica 9 to enter and solve the following equation $p(x) = r^x$ where $p(x)$ is a polynomial whose coefficients are drawn from a finite field, and $r$ is a primitive root of ...
35 views

### How to choose the OpenCL device to use?

OpenCLInformation tells me that my computer has three available OpenCL devices. How can I choose which one to use for computations? How can I verify that ...
20 views

### ParallelTable and DistributeDefinitions

I have a function in the following form: function[...] := With[ {...}, Table[ anotherfunction[i, j, ...], {i, ...}, {j, ...}, ... ] ] If ...
16 views

### Fitting triangular function with HeavisideTheta

I have a problem fitting a triangular function (like potential vs. time in cyclic voltammetry) with a HeavisideTheta function. I just want to get used to ...
53 views

### Deleting parts from a nested list

I have a very long nested list. Here is a short example: list = {{1.2, {1, 1, 1, 1}, {2, 2, 2}}, {0.9, {3, 3, 3, 3}, {4, 4, 4}}, {1.4, {4, 4, 4, 4}, {5, 5, 5}}} ...
40 views

### How to plot a 2D region when there are 3 free parameters?

How could I obtain the region of payments, with the parameters a,b,c,d between 0 and 1 and the sum of all equals 1? After the comment/recommendation of belisarius... I edit the original question ...
23 views

### how can I generate a table for the standard normal distribution?

how can I generate a table for the standard normal distribution? I started with dis= NormalDistribution[0, 1] F [x_]:=PDF [dis, x] Then what?
40 views

### Creating a standalone (executable) from mathematica code

I have written a small mathematica code to input a ".csv" file and output the data in a specific format, in a ".txt" file. I would like to give this program as an executable to my friend as she ...
53 views

Let S[p] denote the sum of digits of p. A prime p is said to be stubborn if none of ...
40 views

I'm working with Vectors type in Mathematica 9. For this purpose I use the following command: ...
124 views

### How to plot and find the volume of a solid?

How to plot and find the volume of the solid enclosed between the paraboloid z=5(x^2+y^2) and z=6-7x^2-y^2 And the answer of ...
75 views

### Visualize difference between members of the list

I want to visualize the difference between members of a set: set = {20, 36, 70, 96, 152, 301} This way I get the diffs: ...
100 views

### How can I find the sum of the even digits of a number of all elements of a list?

Let $E(n)$ denote the sum of the even digits of $n$. For example, $E(123456789) = 2 + 4 + 6 + 8$. I tried a = IntegerDigits[123456789] and ...
37 views

### Hyperlink shrink the image, how to make the image become original size

I found that Hyperlink[im, "something", ImageSize -> 800] The ImageSize only add some borders of my ...
30 views

### Kramers Kronig Relation for Phase and Complex Reflectivity

I am a new user to mathematica and I have been trying to figure out how to find ϴ(ω) from my experimental values of energy and ...
19 views

### shortcut conflict: My Default Stylesheet was broken by one of my personal stylesheet?

My Default Stylesheet was broken by one of my personal stylesheet? I've added one shortcut to one of my stylesheet, Ctrl+Shift+I, to change a style of cell into style named ...
38 views

### How to parse a .css file generated by Mathematica? modify values, add some values

How to parse a .css file generated by Mathematica (Export notebook to HTML)? modify values, add some values. convert into a expression? Are there some instances? I've wrote a simple function to ...
77 views

### Finding a 3d curve from torsion and curvature with NDSolve

I'm trying to use the Frenet–Serret formulas to find the curve that matches the torsion and curvature I specify numerically with an InterpolatingFunction. The ...
36 views

As part of a larger program, I need to solve $A x^2+B x+C \equiv 0 \mod p^k$ for prime $p$. Right now I'm doing this by calling ...
17 views

### How can I prove characteristic equation [on hold]

How can I prove the number 4 question?
22 views

### Subgraph, HighlightGraph not acting as expected

I'm trying to create a simple graph from a matrix and then highlight a particular subgraph. My code (simplified from a bigger task) is as follows. I keep getting the "Subgraph::graph: A graph object ...
121 views

### Elegant high precision log1p?

Sometimes it is hard to understand how numerical expressions are evaluated. I remember reading claims by Wolfram on how smart the Kernel is to evaluate expressions trees numerically by recognizing ...
46 views

### How can I generate the truth table to prove this?

how to generate the truth table to show that p→(q or r )is equivalent to (p and ~q )→r?? Can I use BooleanTable??
28 views

### Alternate method of conjugation using replaceall

Mathematica really struggles to simplify complex conjugates of complicated expressions - even given assumptions for every symbol in the expression being real. Often times I've found that I can ...
70 views

### Module that finds the sum of digits of any given positive integer

How can I make a module that finds the sum of digits of any given positive integer? I use this command F[x_]:= Apply[ Plus, IntegerDigits[x] ] Is there another ...
435 views

### Elegantly split a matrix into positive and negative parts?

I have a matrix $M$ of real components, and I want to split it into two matrices $M^+$ and $M^-$ of the same dimensions as $M$, where $M^+$ contains the positive components of $M$ (the remaining ...
28 views

### No response from DSolve

Using optimal control theory, I am trying to find the optimal paths of d and k such that they will maximize profit as given by lc: ...
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54 views

### How to use ParametricPlot Wih Conditions (or similar)

I´m analizyng the game "Battle of the Buddies" similar to "Prisioner´s Dilenma" All works fine, BUT... I want to draw in red the point whose coordinates are less than the coords of a strategy. ...
79 views

### How to do subtraction with sets in which the elements have multiplicity indicators? [duplicate]

I want to do subtraction with sets l1 and l2, which contain multiplicity indicators. For example, ...
93 views

### Extracting coefficients from g=a*x+b*y+c*x*y

I have a Response Surface Equation (RSE) that I'm trying to extract coefficients from. It has a form similar to: g = a*x + b*y + c*x*y; I want to be able to ...
27 views

### How to Align two inline cells

I'm playing with this question: here and here ...
98 views

### Table iteration over two ranges

I am trying to create a Table where the iterator has two ranges with different iteration steps. Let's consider a simple example: I want to find the square of the ...
19 views

### The value of PageWidth doesn't work for saving as HTML?

CellPrint@Cell["Test","Text",PageWidth->300,Background->Red] And I got this snippet of HTML code： ...
77 views

### How to add the pause button to that dynamic stopwatch?

Referring to How to make a dynamic stopwatch? Timers can now be created with timer = makeTimer[] and utilised with actions such as ...
60 views

### Return “true” if point is in Convex Hull [duplicate]

I have a set of points Z: Z = {{x1,y1},{x2,y2},..,} I would like to obtain a function that returns ...
38 views

Is there any way to find distinct prime factors for very large numbers using Prime and/or PrimePi that exceeds the ...

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