5
votes
1answer
678 views

How to extract a possible closed form from WolframAlpha[] output

To find a possible closed form of a number, I can use the function WolframAlpha["6.38905609893065", IncludePods -> "PossibleClosedForm"] It returns a result ...
1
vote
0answers
79 views

Introducing new variables implicitly [duplicate]

I have a calculation expr111 = cs[giso, xiso, 1, 1, 1] that gives the result -((k x)/(2 (1 + 1/4 k (x^2 + y^2 + z^2)))) ...
5
votes
2answers
508 views

Is Mathematica 8 compatible with Mac OS X 10.9?

Does anyone know if Mathematica 8 works with OS X 10.9?
9
votes
2answers
968 views

How to draw line connecting points on circle

Consider the list {1,2,3,4,3,4,2,1}. I want to label these points on circle the way they appear on list(clockwise, counter clock wise doesn't matter). After that I want to connect same points by ...
1
vote
1answer
566 views

ListPlot and ColorFunction [duplicate]

I've been searching for the use of ColorFunction as an Option for ListPlot, but haven't found anything about it in the documentation. When trying the code ...
3
votes
2answers
173 views

Rook walk and RecurrenceTable in Mathematica

This appears in a combinatorics book: $a(m,n)=2 a(m,n-1)+2 a(m-1,n)-3 a(m-1,n-1)$ It is a recurrence equation for the number of rook walks from $(0,0)$ to $(m,n)$. The initial conditions are: $ a(...
6
votes
2answers
221 views

How to use WhenEvent with a vector ODE in NDSolve

I have an ODE system I'd like to specify as a vector equation in NDSolve. I'm not clear on how to use WhenEvent for a system ...
0
votes
1answer
349 views

How to define a function with different types of arguments by setting conditions on function's domain?

I need help in order to properly define a function of $4$ variables. Given that: ...
3
votes
1answer
261 views

Why cant Mathematica 9 interpret this unit?

I'm using Mathematica 9.0.1. Sorry for using an image, but pasting code messed up the output formatting. I'd like to represent 25 Btu/(hr ft F). All units are spelled correctly as identified in ...
7
votes
2answers
296 views

Inaccurate plot

Could someone please tell me how I can increase the accuracy of this plot, please? Or is there some other reason the lines are breaking up? ...
12
votes
3answers
326 views

Wrong numerical value while exporting to a JSON string

The following code: ExportString[{"a" -> 2000000., "b" -> 0.000001}, "JSON"] Gives the results ...
0
votes
0answers
150 views

Compute (Co)Variance of Random Variable(s) Directly

Is there a direct command in Mathematica that computes the covariance between two random variables? Hence, instead of typing ...
0
votes
0answers
32 views

Find repeated groups in a long algebraic expression [duplicate]

I have an algebraic output (a solution to a de) similar to, but far longer than: {y->(x+3)^2/sin(7*(x+3))+(x+3)^3/7} I'd like to get Mathematica to notice that the group x+3 appears repeatedly, ...
1
vote
1answer
108 views

using rules to look up values

I have a lookup table with about 30 rows. Column 1 has the value I want to search for and column 2 has the value I want returned. It seemed like I should be able to use rules to do this, but clearly ...
2
votes
0answers
108 views

Benefits of using Intellij IDEA as Mathematica IDE? [duplicate]

I use Intellij IDEA for Java programming, but have not really considered it for Mathematica. I saw a video with a Wolfram programmer who was describing it as "essential" for him, but from what I could ...
1
vote
1answer
157 views

Printing intermediate calculations in an external file, while suppressing the output in the notebook

I'm trying to construct a text-file that contains all the operations that Mathematica performs when evaluating an expression. However, i'd like to suppress all output in the notebook in which I'm ...
3
votes
1answer
175 views

How to identify segments of colour and compare

Imagine a wide screen image projected from more than one video projector. Each projector handles a segment of the screen. The overlapping areas are corrected for within each projector. Before ...
5
votes
1answer
462 views

windrose with data from Excel

How to Import data from excel and use them to Plot windrose instead? Example, {{Strength, Angle(degrees)}..} ...
18
votes
1answer
866 views

Two ways of map a function on the list: Which one is faster?

There are 2 ways to make a function listable on the list: Use Map or use SetAttributes. My question is, which one is faster, ...
1
vote
1answer
159 views

DSolve bvfail “For some branches of the general solution, unable to solve the conditions”

I have a problem with the DSolve function and its usage: ...
12
votes
3answers
2k views

Monitoring progress of long calculations

I've came upon a few methods of how to display "processing" information while Mathematica is running. But, from what I've understood, this only works in between lines of codes. Is it possible to ...
12
votes
1answer
690 views

How to find a specific color in one picture?

In a picture, there are many different colors. How can I just want to find the position of one color. In the following picture, if I would like to find the coordinates of the position of blue, how can ...
1
vote
0answers
115 views

Problem in exporting a plot with background to pdf

Just wondering if someone could help me for this problem. I have utilised prolog to use a jpg image as the background of my plot in order to compare my results with ...
1
vote
1answer
104 views

Solve failing and not clear why

I define the function: w[q_, n_, a_] := q/(4 Pi n r^2) (1 - Exp[-2 r/a] (2 (r/a)^2 + 2 (r/a) + 1)) I then want to solve: ...
5
votes
1answer
249 views

Implementing Bilinear Products

Consider a real, vector space $V$ with basis $B=\{v_1,v_2,\dots\}$, and let $\star:V\times V\to\mathbb R$ be a bilinear product on $V$. I would like to implement this product in Mathematica by ...
4
votes
2answers
1k views

ParametricPlot3D with three variables

ParametricPlot3D can be used with one or two variables to plot paths and surfaces in 3-D such as ...
1
vote
0answers
44 views

How can I convert a matrix into matlab form string? [duplicate]

How can I convert a matrix into matlab form? ...
1
vote
1answer
76 views

Avoid unnecessary truncation

Is there any way to change the general settings in Mathematica so that when I type e.g. 0.34*60000000 I get the output ...
3
votes
1answer
93 views

How can I programmatically remove tagged cells without scrolling to them?

I've learned a rather succinct way to delete tagged cells using NotebookLocate, but I would prefer the notebook did not scroll to the selection just for a delete ...
7
votes
3answers
258 views

Why does Mathematica not seem to know that $i^x$ cannot be equal to $0$?

I am experiencing a curious behaviour of Simplify when handling expressions involving powers of $\mathbf{i}$, such as $\mathbf{i}^x$ where $x$ is unknown. For ...
3
votes
4answers
295 views

Padding and formatting within BaseForm

I find using BaseForm to be a little tricky. For example, if you use BaseForm and then do some additional operation all the numbers turn back into base 10, so you have do BaseForm as the "last step". ...
5
votes
2answers
545 views

Intersection of two splines

I have a collection of sets of points, each set defining the segment of a (nice) curve on the unit sphere $S^2 \subset \mathbb{R}^3$. The points are computed numerically. I now want to compute the ...
3
votes
2answers
431 views

How to delete all rows in datafile that contain a string

I'm importing some data from a file. However, the file was created by an unreliable instrument, such that the data looks like this: ...
2
votes
2answers
255 views

Incorrect numerical derivative of function that uses FindRoot

I am trying to plot the derivative of function g[x] below where g[x] is defined as the root of another equation. However, I am ...
1
vote
2answers
296 views

Importing numerical data from RTF file

This might be a very simple question but I have been struggling with it for a couple of hours, so thought maybe someone here can show me a quick way of solving it. I have a file in rtf format (...
4
votes
1answer
290 views

How could I improve this Central Limit Theorem demonstration speed- and content-wise?

My purpose is to demonstrate the Central Limit theorem by assuming two custom distributions, taking some random samples, calculating their means and ploting the results. Ideally, the histograms should ...
4
votes
2answers
354 views

How to make the computer consider two numbers equal up to a certain precision

My problem is that I have a matrix A and the computer says is not Hermitian (self-adjoint). Then I check which elements make A ...
5
votes
2answers
753 views

Problems with Symbolic summation over unknown values

I'm having some real trouble with Mathematica wrongly evaluating various symbolic sums at the moment. I have this function: $$h_{ij}(x) = \binom{j-1}{i-1}-\sum_{r=0}^{j-x-n-(k+1)/2-1}\binom{r+x+n+(1-...
0
votes
1answer
113 views

Truncate a fractional value to particular number of bits?

If I have a fractional value, how can I truncate (not round) that to a certain number of bits, like 8? For example, for Pi 3.141569265359... the fractional part is 0.141569265359... ...
3
votes
1answer
265 views

Read C-formatted hexadecimal numbers?

I have a lot of 32-bit numbers in hexadecimal symbolized as they are in C (for example, 0x1230abde). How can easily read these in Mathematica?
8
votes
2answers
551 views

No builtin function for bitwise rotation?

There appears to be no builtin Mathematica function for bitwise rotation. Is that true? I suppose I can write my function: ...
3
votes
3answers
100 views

How to get different items in a list to interact to get a result?

I have two lists, for example (the real lists are much longer): list1 = {1, 2, 3, 4, 5, 6, 7}; list2 = {9, 10, 11, 12, 13, 14, 15}; I want to create a single ...
7
votes
1answer
318 views

Limit for Matrix expression

Let's assume that $Q_0$ is $3\times 3$ matrix with $\det Q_0\neq0 $ and $$ Q_{i+1} = \frac{1}{2}\left[ Q_i+(Q_i^{-1})^T \right] $$ I need to find next limit: $\lim _{i \to +\infty}$$Q_i$. In other ...
-2
votes
2answers
626 views

Problem with convert matlab function into mathematica version of euler angle

I've wrote a function that will extract euler angle from matrix according to Matlab's function in AeroSpace toolbox's dcm2angle package file. But not quite right. ...
1
vote
1answer
301 views

Manipulate with variable number of sliders plus variable number of functions

I'm trying to setup a Manipulate where I have a variable number of sliders similar to this one, where every slider controls a function. In my case, there will be an additional slider which sets the ...
3
votes
1answer
372 views

How can I produce a branch cut in a surface plot based made with ListPlot3D?

I need to create some surface plots, based on a function that is computationally expensive (a few minutes per point). The function has some branch cuts. The command ...
1
vote
1answer
116 views

Document settings for online viewing

I'm trying to figure out how to prepare a notebook for NICE online viewing when it's been converted to PDF form. The students I am working with (sadly!) will not be able to use the CDFPlayer to view ...
5
votes
1answer
521 views

Why is Plot3D giving me a surface with gaps?

I am trying to get plot for the band structure for graphene. ...
0
votes
1answer
606 views

How to force Mathematica not to use Erf and DawsonF functions in its output

In ODE solutions Mathemathica uses Erf and DawsonF functions instead of the integral expressions they represent. How can I force ...
0
votes
0answers
67 views

kernel shuts down during listplot [duplicate]

In at least the following situations, I have experienced that the kernel has shut down during evaluation. The thing is that there is no message at all when it shuts down. ...

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