1
vote
1answer
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 ...
4
votes
1answer
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 ...
5
votes
0answers
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: ...
5
votes
3answers
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 ...
0
votes
0answers
44 views

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 ...
2
votes
1answer
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 ...
1
vote
1answer
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. ...
6
votes
2answers
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 ...
3
votes
0answers
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 ...
1
vote
0answers
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: ...
0
votes
0answers
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 ...
3
votes
2answers
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? ...
0
votes
0answers
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 ...
9
votes
4answers
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 ...
1
vote
1answer
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 ...
2
votes
3answers
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 ...
2
votes
1answer
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. ...
1
vote
1answer
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. ...
7
votes
2answers
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?
1
vote
1answer
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 ...
10
votes
2answers
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 ...
4
votes
2answers
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 ...
2
votes
1answer
81 views

JLink function not producing result

I have a simple JLink function as follows: ...
1
vote
1answer
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 ...
0
votes
0answers
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 ...
1
vote
2answers
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): ...
0
votes
0answers
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. ...
2
votes
0answers
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 ...
4
votes
2answers
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 ...
5
votes
2answers
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 ...
0
votes
2answers
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 ...
6
votes
4answers
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 ...
0
votes
1answer
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 ...
2
votes
2answers
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 ...
1
vote
1answer
179 views

I want change gamma function form into beta function form

I want to integrate below form ...
1
vote
0answers
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 ...
5
votes
2answers
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 ...
3
votes
1answer
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: ...
2
votes
1answer
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 ...
5
votes
3answers
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 ...
1
vote
0answers
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 ...
2
votes
1answer
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 ...
3
votes
0answers
107 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: ...
0
votes
1answer
280 views

Symbolic Constrained Optimization

I have a question regarding evaluating constrained optimization problems in symbolic terms. I would like to perform How can I implement the method of Lagrange multipliers to find constrained extrema? ...
5
votes
2answers
230 views

Single Legend for a Table of Plots

For this toy problem ...
2
votes
2answers
170 views

Generating an editable table that can be used as input

Say I have a number $n_{max}$. I want a command to generate a table like 1 1 2 2 3 3 4 4 ... nmax nmax where the second column is editable, and this table can be ...
0
votes
1answer
65 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 ...
3
votes
3answers
221 views

Simultaneous equations

I am trying to solve two simultaneous equations that are claimed to have 145 solutions but I believe they have 143, I want to check I am right before sending an email to my professor. Mathematica is ...
0
votes
1answer
230 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 ...

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