# All Questions

2k views

### How to sum over a List

list = {11.5575, 11.397, 5.52734, 4.0878, 2.54815, 1.86652, 2.55028, 2.14952, 1.6242, 1.34117} I have a list of numbers. How do I make a function that creates a ...
1k views

### Shuffle product of two lists

I want to do the following: I have two lists {a_1,...a_n}, {b_1,...,b_n} and I would like to build now all shuffles out of this. This means all unions of these ...
266 views

### Typesetting - entering derivative in traditional form

I am trying to work out how I enter a differential in standard notation? I am familiar with using D, but everything I have tried to enter a differential has failed. ...
233 views

### Does Mathematica compute free-form-input on Wolfram servers?

I've just started to use Mathematica and I'm using the free-form input a lot. The computation time for simple problems seems to take a lot of time and my CPU isn't really used at all. I first thought ...
632 views

### Finding all possible solutions to a math mind game

In the example below the letters shall be replaced by numbers. The numbers are from 1 to 9, and each letter has the same number ...
1k views

### How can I get Mathematica to produce better Fortran code?

I am new to Mathematica and I am trying to get to it to produce some expressions in Fortran code. However, it seems that Mathematica will output duplicated expressions, that is, expressions the need ...
929 views

### Create simple table with function of column values

I just want to create a simple table: Three input columns, one output column Call the inputs {x,y,z}, each can take values ...
251 views

### Error Function Integral (Erf)

Any idea how to solve analytically this integral Integrate[(a Erf[a Sqrt[b/(a^2 + b)] c])/(a^2 + b)^(3/2), a] I tried substitution u=a^2 + b, but it didn't work. ...
120 views

### Adding a textfield to the function that I implemented

Adding a textfield to the function that I implemented to represent the tangent or derivative of a function, but I've added so mark errors. ...
175 views

### How does the speed of WriteString compare to other languages?

I'm doing something where the most sensible approach seems to be to open a file and write to it as I process data from some large tables. Old school. While testing the program, I remembered the low ...
285 views

### Table not working with Plot

Because NIntegrate[] does not support parallel computation out of the box, I'm doing a simplified version by breaking the integration limit into pieces and using ...
226 views

### Analysis of many similar x-ray Images

From a 3d x-ray scan, I have many similar slices to analyze. Is there a way to determine the position of the three rectangles and the inner circle?
79 views

### JLink function not producing result

I have a simple JLink function as follows: ...
161 views

### project from a n-dimensional space to 2-dim

let's say that I have a sphere in $N$-dimensions $$x_1^2+x_2^2+...+x_N^2=R$$ If I want to know the projection on the $x_1-x_2$ plane in this case I can figure out myself that is a circle, but how ...
639 views

### How to define the Poisson bracket in Mathematica

If $f,g$ are functions of the independent variables $\{q_1, q_2, ..., q_N, p_1, p_2, ..., p_N\}$, then the Poisson bracket is defined as: \begin{equation*} [f, g] = \sum_{i=1}^N \left(\frac{\partial ...
113 views

### Iteration of multiple functions that feed into each other

I'm trying to figure out how to iterate through several functions that all "feed" into one-another but am having some trouble. Here are the variables: ...
183 views

### Reduce with Integer domain, but receive a rational solution

I want to find the integer values $k$ so that D[f[x], x] has integer solutions. I tried ...
117 views

### OpenSQLConnection error

I used to be able to connect to a SQL Server database. I haven't run this program for a few months. I tried it today and it failed, so I went back to try OpenSQLConnection[] and got the following ...
81 views

### Editing the Virtual Book?

It's my understanding that the Virtual Book (of mathematica 9) is in notebook (.nb) format. It appears to be a very polished style of documentation which I want to reuse (parts) of it to create my own ...
43 views

### Using an Interpolating Function as a probability density function [duplicate]

I have seen a couple of similar questions but have not been able to figure out a solution for my particular problem. I have a probability density function of two variables ...
302 views

### How to create this list more elegantly

There is list containing some $(i,j)$ values of indices. Now i want to create a matrix of dimension n $\times$ m whose entries are 1 for the indices corresponding to the given list otherwise its ...
24 views

### Create a (maybe nested) list of nminimize solutions in a loop [duplicate]

I'm a total newbie in mathematica, so need some help. I understand that my question is about basics, but i couldn't find the answer in docs, google and here. Here is what i'm trying to do. ...
63 views

### Autoupdate Section Numbers? - Technical Document Authoring with Mathematica

Technical document authoring systems are structured ways to create, manage, and update documentation for various mediums such as print, pdf, web, etc. Take a look at this technical document ported to ...
74 views

### Is there a way to redefine the looks of buttons, tabs and other UI elements?

I am looking for pointers on how to redefine UI elements (in the FE as well as in a CDF document). For example: the looks of a button, or of tab elements, and so on. (I don't mean something like ...
1k views

### Discrete Convolution

Ask to compute the convolution of 2 lists, I managed to do so, with what I feel is rather heavy : Let my 2 lists be : a = {1,2,3,4} b = {1,1,1,1,1,1}; The below function adds 0s on each part of ...
100 views

### Coloring selected elements of a list created with Table [duplicate]

I have a function that returns a list of 100+ elements, using Table[]. For simplification, let's assume that it's just ...
97 views

### How could I change the apperance of a button when some hard computation is finished?

I want to have some bottons inside manipulate to calculate some time consuming functions. For example the following code changes its color after the calculation of Total[Range[123456000]] is ...
379 views

### How can I make a customized InputField for date inputs?

I want to make an InputField that only allows a specific date format to be entered. I want to display a field hint in the format "dd:mm:yyyy". Once the user clicks ...
167 views

### I want change gamma function form into beta function form

I want to integrate below form ...
54 views

### plot cropped in large amount when setting Text Style to some specific sizes and in some locations

I make a Graphics and then add Text[Style["b",size] to it. When changing the size, I noticed that the overall graphics gets ...
118 views

### Why is my answer being displayed with “Subscript^(0,1)[a,b]”?

I type in my equations using ctrl+- to make it look nice and my answer outputs in "Subscript^(0,1)[a,b]" form? What is going on? In the answer some bits are displayed with the actual subscripts and ...
380 views

### Use Euler method to solve differential equation

Use Euler's Method or the Modified Euler's to solve the differential equation ${dy/dt=y^2+t^2-1, y(-2)=-2}$ on $[- 2, 2]$. Take h = 0.2 (...
106 views

### What is so special about variable s$? I found a nice bug in Mathematica 9.0.1.0. Could anyone check to reproduce it? Create a file temp.txt with one line: ... 1answer 64 views ### One more question about Assumptions and Integrate There are many questions about assumptions here. Many of them are problem specific. That is why I want to ask a question in the most general way. Why does Mathematica solves this ... 2answers 159 views ### BarChart3D does not print zeros and odd tick positions Note: This is a version 9.0.0 problem that is fixed in 9.0.1. I want to generate a simple 3D view of some frequencies for two variables. I have the counts in a 4x3 matrix, say. This is my bar chart ... 1answer 350 views ### Remove list elements that contain NaN Symbol [duplicate] I have a long list of lists ...similar to g = {{1,2,3},{4,2,7}, .....{1.2,9}}. Occasionally, g contains elements like ... 2answers 593 views ### Keep MathKernel Running In Background - Speed Up Execution Time Background: I'm running Debian on a remote server with Mathematica installed. I have several dozen small mathematica files that are run in cron jobs at unpredictable intervals and updated based on a ... 3answers 510 views ### How to randomly erode a 3D distribution of points with Mma 7.0? Suppose we have a 3D distribution of points, like the spherical ball example below : ... 1answer 418 views ### How to generate this fractal-like 3D distribution of points in Mma 7.0? I would like to produce some 3D distributions of points using Mathematica 7.0, that look like the picture below : How could I do that ? What are your suggestions ? What Mma 7 codes could do a ... 0answers 109 views ### Problem importing individual frames from QuickTime file I am having difficulties with a code I am trying to run. Essentially I want to Read in a large .mov video file (60000+frames). ... 1answer 223 views ### Plotting a line segment from the degenerate case of an ellipse [duplicate] An ellipse degenerates into a line segment when the defining constant distance from the two foci is the actual distance between the two foci. The ellipse closes into a line segment. The following ... 1answer 124 views ### Product of non-zero elements in sparse array How can I multiply the non-zero elements of a SparseArray? Example: ... 2answers 95 views ### How can I get a fully functional FittedModel when fitting data to a pointwise function? When I am fitting data with a pointwise function using NonlinearModelFit, the produced FittedModel fails to calculate variances ... 1answer 116 views ### Integration of DiracDelta I just came across the following curiosity and I'm not sure whether it's a bug or just me missing something. Here's a minimal example: I defined the following "function" ... 1answer 175 views ### How to compute the residue of$e^{z-\frac{1}{z}}\$ at z=0?

I've tried the following but it didn't work: Residue[Exp[z - 1/z], {z, 0}] not even this: Residue[Exp[1/z], {z, 0}] ...
150 views

### trouble with Dynamic range in SetterBar

It appears that I can set the range to a Dynamic variable in a Manipulate control, but not in a ...
353 views

### Drawing a shape on the mesh of a Plot3D [duplicate]

My question pertains to modifying the output of a typical Plot3D object, and overlaying a 2D shape, like a circle, on the 3D surface. Thinking of the surface as a stretchy surface, I want to put the ...
101 views

### How to align cells in a grid?

I would like to align the text in the gauge such as the label "AKs" is in the center of the gauge and the value (60) is in the upper right corner with a smaller font. How can I achieve this? I tried ...