Questions on the manipulation of List objects in Mathematica, and the functions used for these manipulations.
1
vote
2answers
45 views
Counting a cardinality of a subset satisfying special property
Suppose that we have a set of 9 2-dimensional vectors $c$ by
m=3;
n=2;
c=Tuples[Range[m],n];
We want to define a subset $S$ of vectors in $c$ by the following:
...
4
votes
1answer
115 views
Sorting a matrix alphanumerically
Somewhat related to Sort matrix by columns and rows without changing them, but more general.
I'd like to sort a square matrix (a 3 by 3 in my case, but surely the general solution will treat any), ...
8
votes
0answers
178 views
Using Compile to speed up Function with PermutationProduct
I have the following fairly simple routine dot involving PermutationProduct that I wish to speed up using ...
3
votes
0answers
72 views
Can the elements of a list always be sorted into a canonical order?
As the title states - does a unique order exist for any Mathematica list to be sorted by the Sort[] function (or as returned by a function that treats lists as sets)?
While I'm pretty sure the answer ...
3
votes
0answers
161 views
Find all permutations with reversals / cyclic permutations removed
I have a list of all non-cyclic permutations of n labels. How can I get rid of all elements which are redundant in the sense that they are the inverse of another one. For instance if n=4, the ...
2
votes
0answers
88 views
Derivatives of list elements
Could someone explain the odd behavior of the Derivative function when drawing arguments from lists? We have,
...
2
votes
0answers
194 views
Generating a function which outputs possible chemical reactions
I want to make a list of chemical reactions and I write them down in a $\require{mhchem}\LaTeX$ format. They are of the following form
$$NA_n^i+MB_m^j \rightarrow \hat NA_{\hat n}^{\hat i}+\hat ...
1
vote
0answers
39 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 ...
1
vote
0answers
101 views
Transferring a list from one notebook to another
I have Mathematica code split into two notebooks. The first part is supposed to run and output a list of numbers into a text file, using Export. The second part ...
1
vote
0answers
197 views
About doing an integral
For a given integer $N$ and some function $f(x,y)$ I want to be able to do an integration of the kind,
$\int_{0} ^{\infty} \prod_ {i=1}^N da_i e^{[\sum_{n=1}^{\infty} \frac{1}{n} \left[ N + ...
0
votes
0answers
52 views
Problems with ListDensityPlot
I have the errors in one quantity $x$ in a List form as $(\Delta x,z)$, being $\Delta x$ the error and $z$ the value in which $x$ has the respective error. I want to make a density plot of the errors ...
0
votes
0answers
77 views
Monitor the list for changes
I wrote a function to monitor the list of variable. What it does is if the variable in list change, the changed variable will be separated from others. check the function and output
...
0
votes
0answers
63 views
How can I solve this system of functional equations?
I would like to use Mathematica to find maps a, b, c, d, e, f such that
...
0
votes
0answers
55 views
How to combine file data chronologically via reading numbers in a filename and put it in one list?
Say I have a bunch of files with nearly same filename, eg. data_timestep1, data_timestep2, ...
The data itself in one file is ({x1, y1, z1, absolute field value 1}, {x2, y2, z2, absolute field value ...
0
votes
0answers
62 views
-5
votes
0answers
79 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?
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