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

learn more… | top users | synonyms (3)

0
votes
0answers
63 views

Why are my associations not consistantly followed? [on hold]

I'm working on a code that automatically reorders the words of a phrase. I'm getting some inconsistencies with the word "glass". EDIT: Sorry for not simplifying the code to a basic example. Here's a ...
1
vote
3answers
298 views
+100

Matching the order of a master list of lists from a random list of lists

Using Mathematica 9, I have 2 lists of lists one master with dimensions {300, 6}. The second is some random order but has the same first ...
0
votes
1answer
42 views

Applying multiple functions to a single column in a table

I've seen similar questions, but I'm having trouble applying solutions found there to my situation. My sorting function: ...
1
vote
1answer
50 views

Sorting the words of a phrase by defined variables/associations

Is it possible to change the word order of a phrase by creating a list of possible values/variables and using the Sort function? I want a specific word order always. $(a>b>c>d)$ But the ...
1
vote
2answers
215 views

Use of Sort with custom functions

As mentionned in the topic title, I try to apply my own sorting functions to a set of elements via the Sort command. I make here a quick presentation of the subject before. 1) Method We will ...
23
votes
4answers
3k views

Sort data after specific ordering (ascending/descending) in multiple columns

I have some data: data={{"a", 1, 1}, {"a", 1, 2}, {"a", 1, 3}, {"c", 2, 1}, {"b", 2, 2}, {"b", 2, 3}, {"c", 3, 1}, {"a", 3, 2}, {"a", 3, 3}} When I ...
3
votes
1answer
77 views

Plotting eigenvalues smoothly

I am trying to plot how the eigenvalues of a matrix change by changing a given a parameter t. Of course the ordering of the eigenvalues does not matter mathematically but it does when I want to make ...
6
votes
3answers
290 views
6
votes
3answers
946 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 ...
2
votes
0answers
31 views

How to sort data as in Excel? [duplicate]

How to create a program in Mathematica to sort data (table with several variables) by different variable, by clicking the name of the variable, much like in Excel with freeze pane?
15
votes
4answers
486 views

Reproducing a ranking function that behaves like Excel's RANK

I tried to find a function or expression in Mathematica that produces the same output as the RANK function in Excel (see its description here), but unfortunately I ...
3
votes
2answers
80 views

Problem with Custom Sort/Split/Gather

Please help me Sort/Split/Gather/Group(by) a set of symbolic expressions! (extreme TL;DR at bottom) I have a set of symbols (which represent 2-vectors in a plane, ultimately) and I want to ...
2
votes
1answer
66 views

How to check a clockwise direction for a list of point [closed]

Suppose that we have a list of points and we need to order them in clockwise direction by starting from a special point. I implemented this code to order them but I need to detect if it is ordered in ...
21
votes
2answers
787 views

Ordering problem

Let's look at the following example. Ordering[{0, 20 Sqrt[5], 40 Sqrt[5], 20 Sqrt[5], 20 Sqrt[10]} // N] gives the right answer ...
9
votes
3answers
309 views

GatherBy/SplitBy and Sort a list

So let's say I want to group a list of points based on their distance from the origin. I would do something like: ...
3
votes
2answers
87 views

Role of Accuracy in numerical evaluations, SplitBy vs GatherBy

This is a follow-up question to this question. I generated a list by substituting the results of a solve[] routine and set: ...
1
vote
0answers
33 views

Order of importing data from files

I have many text files numbered from 1 to 1 million in numerical order. Within each text file is 5 columns of data (TAB spaced) with many rows. I effectively want to take the minimum value from each ...
0
votes
1answer
57 views

Can't sort my list numerically for larger numbers than 10 e.g. 1,10,100,2 [duplicate]

I want my files names in real numerical order so 1,2,3,10,12. However it is currently putting them in order like so: 1,10,12,2,3 Input: ...
2
votes
1answer
240 views

What is wrong with my user-defined ordering function?

I've defined ordering function: myOrderingFunction[arg1_, arg2_] which always return True or ...
3
votes
1answer
153 views

Sort by returning positions

How can I computationally efficiently sort a list so as to return the positions and not the actual values at those positions (which SortBy does)?
4
votes
3answers
91 views

Change Contour Plot Overlap Ordering

I have a contour plot for which I have selected a finite set of contours. However, the contours overlap in some places and I would like to reverse the order in which they are drawn. In other ...
3
votes
0answers
296 views

Negative power instead of fraction [duplicate]

Solve returns a solution in the form {{ x -> y / a^2 + y^2 / a^7 }}. Since I want to process the input (with another program) in terms of Laurent polynomials, I ...
1
vote
0answers
61 views

Finding correct combination of functions

I am trying to write code where I have an array $S$ or numbers in any order [5,4,2,1,....] Then I have a specific set of functions that I can write. ...
20
votes
4answers
415 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
58 views

Unexpected result from Sort with symbolic values

I think Sort should be able to sort symbolic values that are reducible to numerical values, but this example seems to get a wrong answer (here is a simplified ...
2
votes
2answers
45 views
5
votes
1answer
94 views

How to order a list to match the order of another list?

How can I order a list to match the order of anoter list ? For example: Suppose I have the lists x = {3, 1, 5, 7} and ...
3
votes
1answer
74 views

SortBy behaving strangely with missing data

I'm trying to create a grid that shows the largest data value from a list. What I have mostly works- the problem comes when there is missing data. You can't really tell here, but all of the ...
11
votes
5answers
440 views

How to sort list of mixed types of elements with each type a specified canonical order?

For example, here is a list {{1, "u"}, {6, "d"}, {3, "u"}, {4, "d"}, {2, "u"}, {5, "u"}, {3, "d"}, {1, "d"}, {4, "u"}, {2, "d"}, {5, "d"}, {6, "u"}} The ...
7
votes
2answers
289 views

Wolfram Language symbols by their Ranks

I'd like to get the top 50, the bottom 50 and an ordered list of all Wolfram Language symbols based on their "Ranks". With ...
0
votes
1answer
46 views

Sorting in descending order of list [closed]

I have a list m = {{a, 20}, {b, 10}, {c, 50}, {d, 5}, {e, 100}} and I want to apply Sort on this in descending order on ...
3
votes
2answers
226 views

Exercise using Sort

I have to order the following list according to the sum of the powers of each element of the list, using the function Sort. ...
4
votes
2answers
115 views

Sorting and keeping the main format of list numbers [duplicate]

I have a list with these elements: list={1/2 (1 + Sqrt[5]), 1, 1, 1/2 (1 - Sqrt[5]), 0}; I want to sort them with ...
1
vote
2answers
125 views

How do I use Subgraph to sample the $n$ vertices of a graph with the greatest connectivity?

Let $G$ be an arbitrary graph with some number of vertices $||V||$ and some number of edges $||E||$. We can use Subgraph to generate, well, a subgraph of ...
6
votes
2answers
399 views

Position function not always returning an answer even with no apparent problems

I'm having some problems with Position. Sometimes it will give an empty list instead of the actual position of the element I am looking for when that element is ...
1
vote
3answers
138 views

Complement[] changes order of elements?

Consider this example: Complement[{a, y, c, d, e}, {a, c}, {d}] (*{e, y}*) However, I was expecting the result to be: ...
2
votes
1answer
59 views

Sort a list of derivatives

I have a list of variables, both constant and functions of an independent variable, including derivatives. I'd like to sort these by the variable name, rather than the derivative order. For example, ...
1
vote
1answer
38 views

Reverse order in evaluated list

I solve the following set of ODE and plot solution of S1 vs k2 (Figure 1). ...
5
votes
1answer
791 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 ...
3
votes
1answer
58 views

Sort Unicode characters

Sorting ASCII phrases works fine: Sort[{"albatrob", "abo", "dict", "star", "mangel", "m"}] (*{"abo", "albatrob", "dict", "m", "mangel", "star"}*) But unless I'm ...
16
votes
3answers
2k views

How to sort colors properly?

I can't seem to be able to sort colors by their hue and perceptual brightness correctly. Here's my current solution, but it's not right; there are all these dark bands: ...
2
votes
1answer
663 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 ...
7
votes
1answer
118 views

Challenging matrix sorting request?

I have an application in mind, and I need to do the following analysis, but am having a high degree of difficulty conceptualizing it in terms of syntax. I understand what I want, but cannot seem to ...
9
votes
2answers
358 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 ...
4
votes
1answer
57 views

How to canonically reorganize a list using only a limited set of manipulations?

I want to canonically reorganize (like Sort) a sequence of four objects seq[a,b,c,d], but the only manipulations allowed are ...
10
votes
1answer
303 views

Lexicographic ordering of lists-of-lists?

I was surprised to discover that Mathematica does not sort lists-of-lists (LLs) lexicographically by default. For example, applying Sort to ...
6
votes
1answer
97 views

SameQ for unsorted lists

I have to compare two or more lists and check if they are the same, but their elements can be in different position. For instance ...