Questions on the sorting/ordering functions of Mathematica (Sort, SortBy, Ordering, etc.).

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4
votes
8answers
370 views

How to sort my list?

For example I have two lists of such structure L1 = {{"Australia",a1}, {"USA",a2}, {"Norway",a3},...} L2 = {{"Russia",b1}, {"Norway",b2}, {"Japan",b3},...} I ...
7
votes
2answers
178 views

Unexpected behavior when using SortBy as a dataset filter

I am still experimenting with datasets. Recently I tried to query the Titanic example to get info on the oldest passengers. Here is what I tried ...
0
votes
0answers
52 views

Ordering oscillators with negative powers: Infinite loops

I have been working with ordering of oscillators for example $[a,a^\dagger]=1$ and I have a fairly stable code. I have needed to use inverse oscillators for example expressions like $a^m ...
0
votes
1answer
37 views

Sort a multidimensional list row-wise [closed]

Suppose I have a multidimensional list as shown below: RandomInteger[{1,10},{3,7}] I obtain the results: $$ \left( \begin{array}{ccccccc} 3 & 8 ...
4
votes
3answers
187 views

Counting number of inversions

Is there an inbuilt method to find the number of inversions in a set of numbers? I found Inversions in Combinatorica but when I ...
3
votes
1answer
56 views

Order imported files by their alteration date

Probably a very easy question, but I could not find the answer, so it would be very nice if you can help me: Let us say I have 10 files, all with the extension ...
0
votes
3answers
82 views

Place symbols from small to big

I am wondering how to compare the different values of ω I derived in this code, and place them in order as follows. (use Print ...
2
votes
1answer
57 views

Sorting a matrix except its last row

Given M = {{"Utah", 2}, {"Iowa", 1}, {"Maine", 3}, {"Total", 6}} I want to obtain the reverse-sorted result like this: ...
1
vote
1answer
70 views

Sort lists of vertices {indegrees, outdegrees} by indegree

in = VertexInDegree[F]; out = VertexOutDegree[F]; I want both in and out to be ordered by in. Example: graph has nodes a,b,c with indegrees 1,2,0 and outdegrees ...
1
vote
2answers
98 views

How to sort the adjecency matrix of bipartite graph so to have two off-diagonal blocks

In a bipartite graphs there are two class of nodes, say A and B. Each node of class A may interact only with nodes of the class B, and viceversa. The corresponding adjecency matrix is thus composed by ...
3
votes
2answers
145 views

Import multiple files from folder in order of date added

I have a folder that contains certain files I want to import. In my case those are .png files. As all the files I want to import contain the phrase "accum" in their filenames, I can use ...
0
votes
1answer
62 views

Sorting a table of vectors with weights [duplicate]

I'm trying to simplify a table, for instance {{1, {4, 2, 0}}, {4, {2, 4, 0}}, {-2, {3, 3, 0}}, {1, {3, 0, 3}}, {-3, {0, 4, 2}}} Here the first column is the ...
0
votes
1answer
66 views

Sorting lists of lists with string elements [closed]

I have a list of sublists. One element of each sublist is a string element. For example: list = {{1, "banana", 3}, {3, "orange", 1}, {2, "apple", 2}}; When I ...
3
votes
2answers
169 views

Sorting a large file

I have some huge logs, which are text files, containing up to a million rows each, and I need them sorted. Because trying to import one obviously makes Mathematica run out of memory, we must rule out ...
0
votes
2answers
50 views

Sorting non-numerical lists [closed]

The Sort function will by default sort from lowest to highest. In[1]:= Sort[{3, 1, 4}] Out[1]= {1, 3, 4} However, if the list ...
2
votes
3answers
255 views

Re-arranging / selecting of a data table very slow in For loop [duplicate]

My task is quite simple; I have a table of data like M = {{1,2}, {1,3}, {3,4}, {5,1}, {6,9}, {6,8}, {6,1}}; so the table is sorted with respect to the first ...
9
votes
2answers
433 views

Rearranging a List

I am trying to rearrange/sort a list i.e. {{1,2},{10,140},{43,10},{1,140},{43,2}} into ...
1
vote
2answers
78 views

Sorting lists with elements that are identical [closed]

How can I sort the following list: list={{1498, 1495}, {1498, 1733}, {1553, 1552}, {1552, 1495}, {1733,1776}, {1776, 1553}}; such that the next group contains ...
0
votes
1answer
65 views

Produce a 1-dimensional list of all unique matrix elements

We have some symbolic matrix m, e.g. m={{1, x, 4 x + y},{0, x y + 4x, 4x},{7 x, x, 4x + x y}} and we want to produce as output a list of all the unique elements ...
2
votes
1answer
195 views

Rank functions of n by their order of growth

I'd like to rank some functions according to their order of growth (e.g. n^2 < n^3). I'm not sure how to do order of growth in mathematica, so I was trying to ...
1
vote
2answers
140 views

Sorting lists element by element [duplicate]

I have a problem regarding list sorting. Let's say I have a list of lists obtained using Subsets[], of the form ...
3
votes
1answer
148 views

Sorting an Array with words in different languages

Array consists of words of different languages. I need to sort elements in reverse alphabetical order and make a list of elements, which consist of english letters. Example of array which consist of ...
3
votes
2answers
302 views

How to plot several functions without jumping? (multiple eigenvalues of a system as functions of 2 parameters)

I've been working on this research problem for months with some success by no global/proper solution to the problem. So I have square, Hermitian matrices of various sizes ($8,20,38$ dimensions) with ...
3
votes
1answer
153 views

Windows Explorer Natural Order

Currently there are a list of notebooks in Windows that I am processing in a folder. Ideally I would like the notebooks to be concated in the same order as how they display in Windows Explorer. I ...
1
vote
2answers
130 views

How to sort Table/Matrix including legend(Labellings)

I want to sort table including its legend for graph I have table similar to M1 M2 M3 1 5 2 3 1 4 4 2 -10 5 7 11 6 -2 1 ...
0
votes
1answer
70 views

Problem with Sort - unexpected order with Sqrt [duplicate]

Sort[{13, Sqrt[157], Sqrt[163]}] (*{13, Sqrt[157], Sqrt[157]}*) Sort[{13, Sqrt[157], Sqrt[157]}, #1 < #2 &] (*{Sqrt[157], Sqrt[157], 13}*) This seems ...
4
votes
1answer
347 views

How to implement Kemeny-Young method? (rank aggregation problem)

Prehistory I am trying to make some statistical analysis of some experimental data, arises from measurements made ​​on an ordinal scale. I faced with the problem of rank aggregation: to get from ...
1
vote
1answer
56 views

How can I sort the polynomial by the degree of $x$

f1 = a x^2 + b x + c + x^3 (* a x^2+b x+c+x^3 *) f1 /. x -> (x - a/3) // Expand (* (2 ...
7
votes
1answer
217 views

How to get all possible orderings (equal ranks allowed) for given set of $N$ objects?

Hope there is a solution besides the tedious generation of nested loops. (Trying to avoid reinventing the wheel.) Here is an example with $N = 3$ objects. There are $13$ needed orderings (first ...
5
votes
1answer
190 views

Efficiently searching a list for the position of the closest number to a specified number

Searching by closest and position I wasn't able to find an answer—but found Nearest by guessing. Nearest, however, returns ...
0
votes
1answer
86 views

Another Sort with multiple criterion

I have a list ...
3
votes
3answers
139 views

Properly ordering the output of FileNames for a directory consisting of files with consecutive integer names [duplicate]

Say I have a number of files in a directory at some location (C:\dir1\dir2\dir3...), and I pull an array of strings corresponding to the file names with the command: ...
11
votes
1answer
278 views

Is there a “precedence table” for the canonical Sort ordering?

This answer in which I wrote about the Operator Precedence Table was unexpectedly popular. That got me thinking about similar things, and I am wondering: Does an "ordering table" exist for the ...
7
votes
2answers
227 views

Complement on pre-sorted lists

Is there any way to instruct Complement to skip the sorting part? If the answer is no (likely), the next question would be: how can I remove from a sorted list ...
5
votes
1answer
163 views

Are there functions or packages in Mathematica to sort subsets in lex order, colex, revlex, etc.?

I am looking for non-canonical sorts of lists. A function that would give: Sort[X, "order type"] With "order type" being colex, revlex, etc.
0
votes
1answer
78 views

Ordering under assumptions

I have a three-element list which contains inverses of a function u, like so: ...
9
votes
2answers
174 views

Why does Sort fail in this simple example?

I'm sure I'll be embarrassed by the answer, but I don't understand why I get the following result: list = {{9, "b"}, {4, "a"}, {7, "k4"}, {6, "k3"}, {5, "w"}} ...
8
votes
4answers
324 views

Gather list elements by index

The following list has some elements that are labeled. For example {1, 2} -> 1, {-1, 3} -> 3, etc: ...
0
votes
1answer
104 views

Sorting a list of triplets by first element of each triplet fails

In the last line of code, I´m trying to order the matrix by the first column. I want to store in the Array t2tlistsorted ( 100 x 3 ), but I can´t. ...
3
votes
2answers
103 views

Non-canonical re-ordering of nested lists

I have some data in the form: ...
12
votes
6answers
523 views

Sort+Union on a list

Probably this is too trivial question for this forum but for some reason I am not getting it on my Mathematica 7 so far. I have a list ...
17
votes
3answers
337 views

Unexpected result {“.a”, “co”, “.m”} from Sort[{“.m”, “.a”, “co”}]

I came across the following situation: Evaluating Sort[{".m", ".a", "co"}] Results in {".a", "co", ".m"} I wondering: ...
0
votes
1answer
136 views

Using Sort vs SortBy

So I have two lists, A and B. I put them into lists = {A,B}I want to sort A such that Im[#1]<Im[#2]& which I can do fine ...
8
votes
1answer
174 views

How to tell when a job is too big for the pattern matcher?

Pattern matching is great but it has its limitations. Consider sorting a list of numbers from smallest to largest: ...
1
vote
1answer
292 views

How do I sort complex numbers?

Okay, so I posted something about sorting, and it was linked as a duplicate to This post However, I am having problems trying to sort a list that contains both real and complex numbers. I put them ...
-1
votes
1answer
98 views

Sorting the element in a PDB text file

I am a new user of Mathematica and currently using version 9. I want to rearrange the element of one PDB text file with respect to another PDB text file. Suppose I have a PDB file like this: ...
5
votes
3answers
391 views

Order list of monomials by degree (Pascal's Triangle)

Suppose I have the following list of monomials: {1,x,x^2,y,y^2,x*y,x^2*y,x*y^2,x^2*y^2} How could I manipulate it to get ...
4
votes
2answers
242 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), ...
14
votes
1answer
202 views

Ordering function with recognition of duplicates

Fairly often I have a need to get the Ordering of an expression but with recognition of duplicates. For example: ...
7
votes
3answers
221 views

Retaining and reusing a one-to-one mapping from a sort

Imagine I sort the elements of an array $Q$ by some means. Perhaps I sort strictly by the elements in the first column, perhaps I use SortBy[...] to sequentially sort by the elements in successive ...