# All Questions

189 views

### Is it possible to give the closed-form of the stiffness matrix of triangular prism element?

Suppose the vertices of triangular prism are 1, 2, 3 (bottom triangle), 4, 5, 6 (top triangle), the coordinates of the vertices are $$(x_i, y_i, z_i), i=1,2,3,4,5,6.$$ We can write the stiffness ...
102 views

### TimeConstrained for parallel computations

The Mathematica manual states TimeConstrained takes account only of CPU time spent inside the main Mathematica kernel process; it does not include additional ...
129 views

### Output most efficient Fortran code by mathematica

I am trying to output most efficient Fortran code by mathematica 9.0 with the method Simon provided: How can I get Mathematica to produce better Fortran code? The expressions is as follows: ...
2k views

### Labeling points on a graph with their coordinates in parentheses

I need to create some graphs in Mathematica with a bunch of labels, such as axes labels, graph labels, etc. In particular, there must be some points that must be labeled with their coordinates. Thanks ...
160 views

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### How to generate closed-form stiff matrix of triangular prism element by mathematica [duplicate]

We can generate closed-form stiff matrix of tetrahedron by mathematica: http://library.wolfram.com/infocenter/Articles/3233/ Can we also generate closed-form stiff matrix of triangular prism element ...
238 views

### Making a rectangular label for RegionPlot

I have a plot that includes a Region Plot. I want to make a rectangle with the same shading as in the region plot to show as a legend. The dumb way I can think off ...
258 views

### Latest Mathematica 9.0 can't use Format.m to generate optimized Fortran code [closed]

Before updating to Mathematica 9.0, I have successfully generated beautiful Fortran code using Mark Sofroniou's Format.m package, which is posted on MathSource. ...
209 views

### Evaluation in lambda function

If I have a function, that returns a function, for example: f[a_] := a^2 * # & then f[3] == 3^2 # & Is there a way ...
278 views

### How to determine BLAS/LAPACK implementation used internally for numerical matrix operations?

Is there a command which reveals which implementation of BLAS and LAPACK are used in Mathematica's matrix operations such as Eigensystem? I asked a related question ...
58 views

### Changing package content in batch

I would like to know if it's safe to do batch operations in a list of package files, applying a function like this: ...
47 views

### Set form of all output to InputForm

I try to interact with mathematica using MathLink for symbolic computations. By default it returns strings such as 2\012-1 + E\012-------\012 3\012 E if the ...
139 views

### Unset while running recursion

I am trying to run a recursive definition while at the same time clearing previously found values, so my memory is not completely consumed. I found this: How to clear parts of a memoized function? ...
29 views

### How to pass rules to packages [duplicate]

EDIT: After helpful comment from @Mr.Wizard I added the working implementation below for future reference. I wrote a module that does something with variables provided in form of a rule. It works ...
600 views

### Find positions of items in a list based on neighbours

How can I select items from a list where the selection criterion depends on the neighbouring items? For example select all indices where a change has occurred with respect to the previous element in ...
156 views

### How to define a summation with function calling itself?

I am new to Mathematica. I want to do this f(x)=summation f(t), summation is over t, where 1<=t<=x-1 and mod(x+1,t+1)=1, i.e. when x+1 is divided by t+1, remainder is 1 and f(1)=1. Should i use ...
145 views

### Applying Labeled Option to Multiple Options

First post. Hope it's not ignorant. I am trying to label several data points so I can label them properly on a ListLinePlot. I know I can label plots if I am ...
288 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. ...
74 views

### Reducing a multi-variate polynomial to have terms upto certain degree

I have a polynomial in x and y. I want to keep all the terms with (combined) degree 4. Any pointers will be appreciated. Simple tricks for doing the same with univariate polynomial don't seem to work. ...
234 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?
240 views

### Numerical saddle point problem of a function of many variables

I want to find the following saddle point of the function of 10 variables: . I am not able to find the stationary points by setting the first derivatives to 0, so I need do optimize the function ...
354 views

### How to take derivative of parameterized coordinate?

Suppose I have a vector in $\mathbb{R}^n$ but $n$ is not known in advance. I want to be able to write functions which operate on the components of that vector, and then I'd like to be able to take ...
165 views

### Capturing an F1

I teach an Intro to Mathematica course, and one of the things I try to reinforce early on is just how helpful Mathematica's help is. In the very first lab for the course, I even give the students a ...
81 views

### JLink function not producing result

I have a simple JLink function as follows: ...
84 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 ...
44 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 ...
171 views

### How to make a single-variable out of a NDSolve solution?

So I've got this line that contains the solution of a partial, non-extraordinary differential equation (because Mathematica doesn't handle extraordinary partial differential equations): ...
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. ...
64 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 ...
291 views

### Detecting changes of variables' values

Is it possible to detect (and create a trigger for) an event when any of the variables defined in the notebook changes its value (for any reason)? I need to know which variable got changed and what ...
303 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 ...
110 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 ...
521 views

### How to find an approximate solution in a region when Solve or NSolve does not work?

Consider the relation x/Tan[Pi x] == y/Tan[Pi y] Solve or NSolve can't give a solution ...
77 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 ...
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 ...
179 views

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

I want to integrate below form ...
55 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 ...
180 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 ...
316 views

### Solving a constrained vector system with NDSolve

I'm trying to replicate the pendulum DAE example in the Documentation Center (example/ModelConstrainedSystemsAsDAEs) using Mathematica 9's vector support with NDSolve. So far I have: ...
165 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 ...
694 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 ...
127 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 ...
126 views

### Change locator object appearance inside Manipulate

I have read earlier discussions of changing Locator appearance in Manipulate. I would like to change the rendered size of the locator object based on one of the manipulate variables. I can't get ...
107 views

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### 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 ...