All Questions
2
votes
3answers
34 views
Why do these two different zetas produce the same value?
Zeta[-13] == Zeta[-1] == -1/12
Why do these two different zetas produce the same value?
0
votes
0answers
4 views
Import/Export Cluster Object
I want to export and then import back in a cluster object from Agglomerate. After the import, the imported object does not behave as a cluster - for example, ClusterSplit does not recognize it as a ...
0
votes
0answers
12 views
Using single replacement rule to convert algebraic expression
I have been trying this problems for hours and cannot find any helpful clues.
How can I convert $Sinh[3\theta]+Sinh[\theta]$ to a rational function of x given $2Sinh[\theta] = x-x^{-1}$ by using only ...
7
votes
1answer
105 views
How can I make a cell that contains an image which can be shifted?
When you look at some help pages, they may have cells containing images which are movable within the cell when you left-click and drag the mouse.
Here is a sample: ...
0
votes
0answers
14 views
5
votes
3answers
91 views
Applying a function with the HoldAll attribute inside NestList
I'm trying to write an update function, which can be applied to a list and then to NestList it.
As the function has to manipulate the given variable I figured I ...
4
votes
2answers
43 views
4
votes
2answers
74 views
Variable scoping problem when mapping over delayed replacement
This is something that got me curious while I was playing around with Mathematica.
Consider the following (contrived) example:
...
0
votes
1answer
55 views
Solve this equation symbolically
I am trying to solve the equation for the quantity r = y/x symbolically:
3/y^4 == 3/x^4 + a/(x + 2 y)^4
with the requirement that we need to perform the ...
1
vote
1answer
38 views
Generating a list of all factorizations
What is the best way to generate a list of all factorizations of some number $n$? I'm quite new to Mathematica so this might be obvious. I have been trying some basic stuff with ...
11
votes
2answers
232 views
How can I compile this function
I want to simplify my function f1 to f2, but f2 can't be compiled. How can I make it ...
1
vote
0answers
15 views
How to create internally optimized expression for computing with high WorkingPrecision?
I have large dataset and need to fit rather complicated function on it with different values of one of its parameters (this parameter must be fixed in every fit). I use the ...
10
votes
2answers
312 views
Is it possible to use the LevenbergMarquardt algorithm for fitting a black-box residual function?
I have a black-box multiargument multiparametric function of the type SRD[dataPoint_List,params_List] which accepts experimental data along with the parameters of ...
0
votes
1answer
29 views
How could I find the correct values for every array that would lead me to unique summation number for every unique chain?
I have 9 arrays, each array has 9 values, I need to get the proper values in every value's position for every array, and that would give my a completely unique summations for every value's chain from ...
1
vote
1answer
38 views
Range of stability for iterative map
Using linear stability analysis, I would like to compute the range of stability of the fixed points and the 2-cycles of the following iterative map: $x_n = x_{n-1}^{2} - 3\mu$.
Setting $x = x^{2} - ...
1
vote
0answers
31 views
Eureqa Client to connect to Mathematica under Windows
Does there exist a way to use Eureqa software with Mathematica under Windows?
That is, is there a working client to connect to a Eureqa server?
1
vote
0answers
25 views
Smooth Kernel Distribution
Smooth Kernel Distribution
Hi
i am in the research of the Silverman Rule of thumb for Bandwidth selection.
Below is a sample of my code, from which it seems that BW=63 is close to the default ...
0
votes
2answers
52 views
How to create a 3D curved surface, given some discrete points in space?
I have some 3D point data and I want to create a curved surface with these points, and export the curved surface data (point coordinates) according to points density on the curved surface. How can I ...
0
votes
1answer
59 views
Doing vector manipulations on Mathematica
This is hopefully a simpler version of this previous unanswered question of mine.
Let me just focus on the two expressions $F_2^{(s)}$ and $F_3^{(s)}$ given in A.3 and A.4 of page 19 of this paper. ...
1
vote
4answers
118 views
How can I create a list of functions?
Can anyone tell me, how to create a list of functions? I've tried the following code, but it doesn't work.
...
0
votes
0answers
21 views
Indexing of Large System of Equations for Use in NDSolve
I currently have a list of ~150 DAE's (differential-algebraic equations) and I need to be able to work with using NDSolve. Fortunately I already have them ...
9
votes
1answer
142 views
Modules that initialize themselves on first call
I use a lot of functions that extract a specific data item from a file with many data items. I want these functions to load data (slow) and return the item (fast) on first call, but just return the ...
31
votes
6answers
676 views
Can one identify the design patterns of Mathematica?
... or are they unnecessary in such a high-level language?
I've been thinking about programming style, coding standards and the like quite a bit lately, the result of my current work on a mixed ...
10
votes
2answers
216 views
Notebook formatting - easier descriptions for equations and results?
When I do computations in mathematica, I generally try to make it readable for myself-in-the-future. This can be a cumbersome task in mathematica, where it often requires me to switch betwee a text ...
-5
votes
0answers
70 views
Extracting points data from a 3D curve surface?
I have a 3D data sets, and I have used it to create a 3D plot, but some of the data points are errors and need to be removed. How I can I remove the bad points from the plot?
...
1
vote
0answers
39 views
Nontrivial solutions of equation
Here I have one problem how to find nontrivial solution of a system of equation. I want to choose one variable, for example X1 and to get solutions of X2(X1) and X3(X1). It is not difficult when I ...
0
votes
1answer
77 views
How to tell Mathematica to make assumptions? [duplicate]
Say I want to integrate 1/(x^2+a^2) and I want Mathematica to know that $a>0$. What would be the command? Something like:
...
2
votes
3answers
132 views
How do I obtain the correct double limit?
The command
Limit[(Sin[x^2] + Sin[y^2])/ (x - y) /. x -> 0, y -> 0]
(*
0
*)
I think that Mathematica finds the iterated limit instead of the double ...
1
vote
1answer
68 views
3rd derivative keyboard shortcut
For a long time i've evaluated D[f[t],{t,3}] to get this power-like derivative thing:
$$f^{(3)}(x)$$
Is it possible to obtain same through an easier keyboard ...
8
votes
2answers
128 views
Adding custom GridLines to the “automatic” ones
I need to add custom (vertical) grid lines to a plot (to a DateListPlot, to be precise). I know there is the option of ...
5
votes
0answers
89 views
Find all the integer numbers $a$, $b$, $c$, $d$, $e$, $f$, $k$ to this equation have three integer different solutions?
How to choose all integer numbers $a$, $b$, $c$, $d$, $e$, $f$, $k$ belongs to interval $[-20,20]$ to the equation $$\sqrt[3]{a x + b} +\sqrt[3]{c x + d} + \sqrt[3]{e x + f} =k$$ has three integer ...
1
vote
1answer
54 views
Dt acting on symbolic notational forms
This one must be simple, but I can't figure out a decent solution.
Suppose, I have a symbol with a notational form applied to it, say OverHat[A].
Now, if I didn't ...
2
votes
2answers
64 views
3
votes
0answers
20 views
Correct behavior of lock file in hsqldb connection
I'm running in to some problems with generating a persistent HSQLDB and during some troubleshooting I came upon the following behavior.
...
8
votes
1answer
152 views
Efficient way to solve equal sums $x_1^k+x_2^k+\dots+x_5^k=y_1^k+y_2^k+\dots+y_5^k$ with Mathematica?
I need to solve the system of equations, call it $S_1$, in the integers
$$x_1x_2x_3x_4x_5 = y_1y_2y_3y_4y_5$$
$$x_1^k+x_2^k+\dots+x_5^k=y_1^k+y_2^k+\dots+y_5^k,\;\; k= 2,4,6$$
I used a very ...
2
votes
0answers
73 views
Why my Mathematica 9.0.1 wont work with some samples of Mathematica in Graph Theory?
I updated my Mathematica recently to 9.0.1 cause the previous version was giving me freaky result especially in FindMinimumCostFlow and ...
2
votes
2answers
53 views
Importing LTSpice data into mathematica
I am working with LTSpice (Discret electrical circuit ( Spice) simulator). I would like to import LTSpice ouput data into mathematica for processing and plots.
An example of a file can be found here ...
35
votes
3answers
11k views
How to create new “person curve”?
Wolfram|Alpha has a whole collection¹ of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica ...
4
votes
3answers
275 views
How to Clear variables with apostrophe?
An apostrophe ' is often used when we want to distinguish two variables. For example, if we already have a variable t and we may ...
6
votes
2answers
1k views
Creating a simulation of our Solar System
As the title says, my objective is to create a simulation of the motion of the planets in our Solar System using Mathematica. All the theoretical background regarding the equations of motion of ...
0
votes
0answers
33 views
Returning a non-degenerate list of triangles that (strictly) define the outer mesh of a 3-polytope using PolyhedronData?
I'm looking for a simple method of returning a list of triangles that strictly define the outer surface of a 3-polytope using PolyhedronData?
For example:
...
5
votes
4answers
115 views
Tricky selection of elements based on their position
I need to make a list of some elements from a 4D array with dimensions 4x4x4x4. I need to select the elements based on their position in the following way: name an element e(x,y,z,w); I need all the ...
3
votes
1answer
67 views
Solving an ODE in power series
How do I find a series solution to an ODE?
I do not mean taking the Taylor series of an exact solution; I want to solve nasty nonlinear differential equations locally via plug and chug. Surely, that ...
0
votes
0answers
39 views
Anti-aliasing won't work when there is PlotStyle command
I've found that if there is PlotStyle command in the input, anti-aliasing will not work.
However if the Style code is ...
0
votes
1answer
56 views
What does Binomial return for non-integer arguments?
Mathematica returns values for non-integer arguments passed to Binomial.
What is the definition of Binomial for such continuous ...
2
votes
2answers
155 views
How can I import images from a Microsoft SQLServer database?
I have a table with binary data (images) in Microsoft SQlServer. I want to import that data and convert it into Image format. I wrote the following code, but it's ...
2
votes
1answer
59 views
Flat function with repeated sequence
There are functions like Join[ ] that accept a variable number of arguments. Join is a flat function, as the order of arguments ...
2
votes
3answers
128 views
Using ImageTransformation[] with a lookup table
I need to transform images by ImageTransformation in a time critical application. Therefore I precalculate a lookup table lut of ...
1
vote
0answers
50 views
How to SystemOpen Mathematica only one time?
Here is my prevous question
When I'm trying solve that question:Reset-$Language— each time open a Mathematica.
Because If I open one English-Version-Mathematica, ...
5
votes
0answers
128 views
