7
votes
3answers
314 views

Find names of the functions defined in a file

Lets say I have a file named file.m that contains: test[] := ( Print["test"] ) How would I go about extracting the function ...
7
votes
3answers
394 views

Combining Image3D and Graphics3D

I want to combine an Image3D and a Graphics3D using Show. Here is the code: ...
7
votes
3answers
271 views

Unencoding encoded URLs in a function

Is there a built-in function for decoding encoded URLs in Mathematica? I would like to convert an encoded URL, for example ...
7
votes
4answers
210 views

Why does array packing in Table behave like this?

Consider the following example, which generate two identical arrays. Why sometimes the array is packed and sometimes it doesn't? And why they perform differently? Here the arrays are packed: ...
7
votes
2answers
394 views

How to generate a matrix group?

I have three $7\times 7$ matrices (with real entries, lots of zeros) and I'd like to check if they generate a finite group (or, more precisely, if the group they generate is of precise order). Would ...
7
votes
2answers
649 views

How to change an expression to Fortran90 form?

I have a large expression produced by Mathematica. To use this expression in my Fortran program I need to change it to a Fortran90 form. I am not satisfied with the ...
7
votes
1answer
282 views

How to change brackets in TraditionalForm output

I'm trying to improve TraditionalForm's output by using different brackets when there are more than one. For instance, instead of $u(v(r(b))))$, I'd like to get ...
7
votes
1answer
793 views

Dynamic Graph visualization

I'm working on a C++ library that will be used to construct and study certain graphs (as in a set of connected vertices, not a function plot). These graphs will be dynamic in nature (and can ...
7
votes
4answers
338 views

How to remove ticks?

I wanted to remove the Ticks in my coding but i can't. Here when i try to remove the Ticks the number also gone. I need numbers ...
7
votes
3answers
394 views

How to Gather a list with some elements considered unique

I have a list of the form: list={{0,...},{1,...},{1,...},{0,...},{3,...},{3,...},{0,...},{0,...},{5,...},{5,...},{5,...},{0,...},{5,...},{0,...},...} So when we ...
7
votes
1answer
247 views

How to wrap this dynamic code inside a Manipulate?

My goal is to set up a Ising-type simulation, where many fast simulation steps are done in the background, and a visualization of the current state is displayed as the simulation evolves, being ...
7
votes
1answer
172 views

Is this a good way to assign a Solve result to a function?

My code: ...
7
votes
3answers
633 views

How to rotate TickMarks in DateListPlot?

Is there a way to rotate TickMarks in DateListPlot to avoid overlap, eg: Part of the code used to generate this is: ...
7
votes
2answers
546 views

Simplifying the derivative of $|x|$

Context In[855]:= D[Abs[x], x] /. x -> 1 Out[855]= Derivative[1][Abs][1] In[856]:= D[x, x] /. x -> 1 Out[856]= 1 Question Why is ...
7
votes
6answers
578 views

Using a built-in symbol as a variable

I want to produce a Mathematica Computable Document in which N appears as a variable in my formulae. But N is a reserved word in ...
7
votes
2answers
2k views

Inverse of a complicated function

Mathematica is struggling to find the inverse of this function f(r): ...
7
votes
3answers
1k views

how to simplify symbolic integration

The following is the code: ...
7
votes
1answer
705 views

How to find the smallest root

I have a continuous, differentiable, monotonic, bounded function called F[t]. If t -> Infinity then ...
7
votes
1answer
565 views

Efficiently deleting rows in many large text files

I have 500 text files each of about 200000 rows. I need to delete one row in each of them as fast as possible (later such operations will repeat). What is the best way to do this with Mathematica? ...
7
votes
4answers
981 views

Force function to make assumptions about its input variables in Mathematica

I'm trying to force a Mathematica function to make an assumption about its input variables. In my case, I'm trying to define a function to return the pdf of a Gaussian. But let's use a simple toy ...
7
votes
1answer
143 views

Organizing similar datasets using Contexts or otherwise

I often import several long time series to analyze something about a city. When I have multiple cities, I use contexts. As a simple example, ...
7
votes
1answer
838 views

How do you get high resolution plots in applications using the Mathematica MathService?

This is for Mac users only using MathService (MathService it seems, given that it was created back in 2004, is a power pc code and requires Rosetta to run on Intel). If I type a plot command in ...
6
votes
3answers
113 views

How to transpose x and y axes on a LogPlot?

Consider the following simple LogPlot: LogPlot[Exp[x],{x,0,5}] Is there a nice way to switch the axes of a LogPlot? I'm aware that plotting the inverse ...
6
votes
2answers
257 views

How to color edges of a graph which has multiple edges connecting certain vertices

I'm studying BIBD(Balanced Incomplete Block Design) and want to draw some graphs by coloring their blocks in different colors, respectively. A block is a collection of edges (or vertices). For ...
6
votes
1answer
238 views

How to use Undocumented Functions Prism, Tetrahedron and Hexahedron

Taking a look at this question and this one, I checked to see if Mathematica really does not have a Prism primitive. To my surprise the function ...
6
votes
1answer
239 views

Map of Specific US States? (Isolated)

My question here is fairly basic, and I'm sure I'm overlooking something basic. I know about CountryData for creating shapes of entire countries, and it works, to ...
6
votes
1answer
337 views

Find the eigenvector associated with the smallest eigenvalue, not smallest in magnitude

I am trying to find the eigenvector of a $20000 \times 20000$ sparse matrix associated with the smallest eigenvalue. I realized that the smallest eigenvalue might be negative; for example, if the ...
6
votes
1answer
91 views

How to understand shared passing of a MTensor in LibraryLink?

According to the documentation, there are four different type of memory managing when passing a MTensor with LibraryLink: Automatic, "Constant", "Manual" and "Shared". The Automatic and "Manual" is ...
6
votes
3answers
452 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 : ...
6
votes
0answers
121 views

Possible bug with FourierTransform linearity

Each component is easily transformed but the sum is not: FourierTransform[f''[x], x, k] FourierTransform[f'[x], x, k] ...
6
votes
1answer
285 views

Having trouble fitting data using NonlinearModelFit

I'm trying to fit data = {{2002, 45000}, {2004, 90000}, {2005, 120000}, {2013, 211000}}; to an exponential function ...
6
votes
9answers
495 views

combining and comparing lists

I have 2 lists (of lists), where most of the contained lists match. That is, the lists contained in list1 mostly match the lists contained in list2. In this simplified example each of the inner ...
6
votes
4answers
560 views

Removing empty sets from lists

If I had a list, say, names= {"Andy", "Bob", "Carly", "Sandy", "Jeff", "Tim", "Tom", "Zach"} and I decide to pick a characteristic only a certain of them have, ...
6
votes
1answer
152 views

The third argument of the Root function

Consider the roots of an arbitrary indecomposable polynomial: sol = Solve[x^5 + 2 x + 1 == 0, x] The returned expression is ...
6
votes
1answer
365 views

Getting clearer StreamPlot output

When I do a StreamPlotof a rather complicated pair of differential equations, it loses some details. For example: ...
6
votes
3answers
126 views

How to simplify my expression to the style of “a+b*I”?

How to simplify my expression to the style of "a+b*I"? Expand[(E^(I θ) (-1 + E^(I n θ)))/(-1 + E^(I θ))] ...
6
votes
4answers
143 views

Hold expression with RandomInteger

One more question for today: I'm trying to show two random integers with a plus (+) sign between them, in an unevaluated form. I know how Hold and HoldForm work, but they hold everything, including ...
6
votes
3answers
484 views

Expression of uncertainty in measurement.

I have a problem with writing a Mathematica function. I have been requested to show the results of my experiments with the measurement uncertainty (mu) like below: ...
6
votes
1answer
226 views

String pattern search and replacement — it works, but produces error messages only the first time it is called

I defined a function in Mathematica to process a pre-generated string. More specifically, I'd like to process some parts of C codes generated from MMA. Basically what my function does is to expand the ...
6
votes
2answers
1k views

How do you put conditions on indices in a sum?

I'm relatively inexperienced with mathematica, so I apologize if this is a trivial question. I want to take a double sum over a function $f(i,j)$ of two indices, of the form $$ \sum_{i = ...
6
votes
3answers
176 views

Is it possible to Import urls not type “”

These days I often copy urls from Internet Explorer's address bar. When I paste the url into a Mathematica cell it is neither a string nor a expression. ...
6
votes
2answers
615 views

Manipulating plot of random iterated function system fractal

I'm generating the Sierpinski Gasket by implementing a chaos game in mathematica. What I'd like to do is create an interactive manipulation with a slider, whereby moving it forward, plots all the ...
6
votes
1answer
162 views

Importing images from the web using ImportString & URLFetch

I can bring images from the web using the Import command like this: Import["http://blog.wolfram.com/wp-content/uploads/2008/06/se-30.jpg"] Sometimes the web ...
6
votes
4answers
615 views

data visualization on a lattice grid

Is it possible to visualize an array whose elements are angles as actual angles on a lattice grid? E.g., say, if the input is: ...
6
votes
2answers
286 views

How can I find if the number of subsets for a list is very large?

I'm trying to find the following; Subsets[Range[2, 2300], {4}] but my computer gave the following error: ...
6
votes
6answers
893 views

Image of first quadrant under $f(z)=(z+i)/(z-i)$

I'm able to plot the region where Im[z] > 0 and Re[z] > 0: ...
6
votes
4answers
417 views

How do I display an expression with negative powers?

How do I display an expression with negative powers? Mathematica seems to always invert a term with a negative rational power. None of the following work: ...
6
votes
2answers
357 views

BoxWhiskerChart with logarithmic axes

I would like to make a following chart Ideally I would also like to control the boxes position on a logarithmic x-axis. Some inspiration how to do the latter may be found in the answer to my ...
6
votes
1answer
301 views

How can I define a function that can accumulate its parameter?

For example, write a function add: add[3] return 3 add[4] return 7 add[10] return 17
6
votes
1answer
266 views

PlotStyle does not work when plotting a non-evaluated list of functions [duplicate]

When a list of functions is passed to Plot in an unevaluated form (e.g. with Through), the result is a plot with single color. ...

15 30 50 per page