-1
votes
0answers
36 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
3answers
97 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 ...
1
vote
0answers
43 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 ...
2
votes
1answer
70 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 ...
2
votes
4answers
145 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.
...
-5
votes
0answers
82 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?
...
2
votes
1answer
60 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 ...
5
votes
4answers
177 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
0answers
55 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, ...
0
votes
1answer
60 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 ...
3
votes
1answer
67 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 ...
8
votes
2answers
138 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 ...
1
vote
2answers
67 views
Overloading conjugate operator for a particular function
I trying to modify the behaviour of the built-in Conjugate[] operator on a particular function I have defined, to take into account that some of its variables are real.
...
0
votes
0answers
2 views
Simple Math Equation find sum of 4 fields and if greater then field y reduce all 4 fields respectively [migrated]
Im not the greatest at Math but i have the following problem:
impressions = 791.
watched 100 = 500
watched 75 = 383
watched 50 = 600
watched 25 = 700
The sum of all watched fields is 2183.
...
5
votes
2answers
193 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 $[-10,10]$ to the equation $$\sqrt[3]{a x + b} +\sqrt[3]{c x + d} + \sqrt[3]{e x + f} =k$$ has three integer ...
4
votes
1answer
87 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 ...
1
vote
0answers
68 views
How to configure two Mathematica Language Version in two places with different setting
I've installed two Mathematica 9 with different language version.
One in Disk D English Version
One in Disk E ChineseSiplified Version
How to configure two different settings ?
because they ...
8
votes
1answer
164 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 ...
4
votes
3answers
93 views
Modify this code using Module and While
I have written a recursive function and would like to re-write the code using Module AND While to compare the timings.
Here is my recursive function for f[n], where 6 n f[n] = f[n-1] + n! for n>0 and ...
5
votes
4answers
122 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 ...
0
votes
0answers
11 views
number property [migrated]
How can you prove that every natural number M or M+1 can be written as k + Sum(k), where Sum(k) represents the digits sum of number k.
Example:
248 = 241 + Sum(241) = 241 + 2 + 4 + 1
5
votes
1answer
126 views
How can I draw a polygon from a set of angles?
In recreational mathematics, polytans are polygons formed by edge-connecting isosceles right triangles. Order-n polytans are those constructed from n such triangles. My question is this:
Given a ...
-1
votes
2answers
81 views
Discrete 3D Plot with date on one axis
1) How do I plot the following data in 3D (large data, only a part of it is used here):
...
0
votes
1answer
79 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:
...
1
vote
0answers
65 views
What is wrong with this PDE?
I'm trying to get a numerical solution to the wave equation but Mathematica keeps on giving me an error and I cannot see what the problem is. This is the code I have:
...
1
vote
0answers
59 views
Distribution above pointplot
This is my first question here, so I'm sorry if I do something wrong.
Also I'm fairly new to Mathematica (using 8). I've used it about 2 months. Only 2 weeks intensive. The rest was about ...
1
vote
2answers
86 views
Can you form a list with elements which are terms from an equation?
Is there a command that takes an equation as an input and creates an output with a list of terms in the original equation? Something like:
...
0
votes
1answer
121 views
Strange 3D plot behavior
Two Part Question
Part 1: As you can see from the data and plot below, the plot does not accurately display the data sets but adds lines beyond and in different dimensions. Both u and v datasets are ...
5
votes
0answers
169 views
6
votes
2answers
102 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:
...
7
votes
2answers
80 views
How to show wireframes on imported Object / Mesh (.obj file)
I've managed to import a Wavefront (.obj) file and store it in a variable like so:
...
2
votes
2answers
161 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
0answers
34 views
How to estimate system recource usage of a SparseArray?
Build a 100.000.000 by 10 element SparsArray.
Fill position 1/1 and 100.000.000/10 with a value 999.999.999.999.999.
...
0
votes
3answers
104 views
List of Tribonacci Polynomials with Mathematica? [duplicate]
I want to list top ten of Tribonacci polynomials. I have following algorithm, but it doesnt work.
...
1
vote
0answers
66 views
Element[ ] for real numbers
I was just wondering that one can easily check the presence of any number rational/irrational in $\mathbb R$ but I could not find if Mathematica supports any notation for open sets.
The number of ...
0
votes
0answers
45 views
Does setting FindMinimum constraints improve efficiency? [closed]
I am a newbie and this my first post.
I am using the FindMinimum function to minimize a function of between $19$ and $35$ variables and I do this about $200$ times ...
2
votes
1answer
79 views
How to combine SparseArray and If
Because I am dealing with huge matrixes, my computer can not handle it, because of the memory. But, in my matrix, a very small percentage of the elements are non-zero. So I should use SparseArray as ...
2
votes
1answer
68 views
What is the underlying algorithm for GroupElementToWord?
What algorithm is Mathematica 9 using for GroupElementToWord[group, g]?
1
vote
2answers
149 views
Translating a “Point-to-Triangle” distance script from MATLAB to Mathematica
Update - Thanks everyone for your responses! After fixing a problem with vector normalization, the code below now works.
I'm a new user, and I was attempting to port some Mathematica code from ...
3
votes
0answers
50 views
Is it possible to run Mathematica on an HPC cluster with Torque?
I'm installing Wolfram gridMathematica in HPC cluster with TORQUE Resource Manager. There is a big problem because Mathematica suppost PBS pro.
Can you help me or give some advice or coments?
0
votes
1answer
31 views
Dynamic Updating CreateDialog Problem
In this code, One cannot close the Dialog:
{TogglerBar[Dynamic[x], Range[5]], Dynamic[x], Dynamic[CreateDialog[x]]}
If I use DynamicModule this way: the Dialog ...
11
votes
2answers
149 views
How to generate characters by a function which works like the Esc + a + ESC
How to generate characters by a function which works like the Esc + a + ESC
...
4
votes
2answers
75 views
Graphics3D: the box vertices do not coincide with triangle
I have drawn a triangle using Line graphics primitive and Graphics3D function:
...
1
vote
2answers
139 views
Write a function that returns the logarithmic derivative
How can we write a function that if we input an expression f, it returns the log derivative $\frac{1}{f} \frac{df}{dx}$. We have to use a conditional or pattern test so that the function accepts any ...
0
votes
0answers
42 views
Strange Error in NDSolve [closed]
I am trying to numerically solve a long list of ordinary differential equations using NDSolve as follows:
...
0
votes
0answers
32 views
How to tell Mathematica to use Real Only Mode [duplicate]
How do I tell Mathematica to use real only mode. For example if I want to graph $(x-1)^{1/3}$ for $-3<x<3$, I need to use Real Only mode to get the right graph.
5
votes
1answer
71 views
Is it possible to save an interrupted computation?
I've got this really time consuming factoring problem. To decouple things a bit, I decided to start Mathematica using the command line interface (under screen).
...
2
votes
3answers
57 views
Problem with simplifying Sinc function
$Assumptions = x ∈ Reals && y ∈ Reals && a ∈ Reals && b ∈ Reals;
These work:
...
5
votes
1answer
65 views
How can I substitute something using only map?
For example, I have the equation
x^2 + y^2 == x*y
and I want to apply the rule
y -> s*x
I can do it easily by
...
0
votes
0answers
34 views
Generating partitions of a set with a specified size of the parts [duplicate]
I tried the following (inspired by the answer here)
myList = {a, b, c};
Needs["Combinatorica`"];
SetPartitions[myList]
and I got this answer,
...
