Questions tagged [sorting]
Questions on the sorting/ordering functions of Mathematica (Sort, SortBy, Ordering, etc.).
329
questions
9
votes
6answers
246 views
How to sort and extract a list containing products
I've some difficulties with lists containing products as elements, e.g. list = {A B A, A K B, A K R}, where A and B are from the same 'family', let's call it sector ...
0
votes
1answer
77 views
How do I ensure the substitution happens after I take the first derivative before taking my second derivative
The title may be a little confusing so let me explain what I mean:
I am using lagrange brackets to produce some equations of motion for orbital mechanics, where the motion is split between oscillating ...
5
votes
4answers
116 views
How do I reorder and combine sublists based on sublist rankings given by another list?
I have two lists:
...
4
votes
2answers
169 views
How do I sort points {ai,bi}; i = 1,2,…,N so that immediate successors are closest?
Suppose there are points {ai,bi}; i = 1,....,N, but this is given in some jumbled order such as
...
-2
votes
1answer
47 views
Sorting of eigensystem accroding to specific eigenvector
I have a matrix, I want to sort it with respect to specific eigenvectors.
Here, I provided an example of a matrix HT:
...
0
votes
0answers
15 views
How to reverse or restore the order of my cells in Wolfram Mathematica Cloud?
I was completing my assignment and I have no idea what I clicked but all the cells got reversed that is the 1st one on the last and the last is the first cell in my file. I want to restore it back. I ...
2
votes
2answers
62 views
Print function value at specified coordinate
Below is the code to evaluate the function.
I am trying to print the function values at a specified coordinate as shown in ActCoor.
...
2
votes
1answer
97 views
Sorting Eigensystem According to Complicated Rule
I have looked for an answer to this but the near duplicates I could find seemed slightly distinct.
I have a matrix $A$ which has eigenvalues in pairs $\lambda_1,-\lambda_1,\lambda_2,-\lambda_2,\dots$. ...
1
vote
1answer
38 views
sorting out the coordinate and respective solution values for plotting
I want to plot for coordinates and corresponding solution values below.
...
0
votes
2answers
66 views
How to select the median of a list?
If I have a list {3,19.5,85,45/2,5.6}, how can I select the median of the list without using the built-in Median command?
First ...
1
vote
4answers
138 views
How would we extract elements of a list greater than a certain value? [closed]
Say we have a list
{35,210,67,950,32,365}
how would we extract all the elements greater than 100 from this list (using a function)? The desired output would be ...
1
vote
1answer
62 views
How to sort the list A in an increasing order, such that I can modify the other list B with change in element position of list A
I have two lists A and B, I am trying to change modify the elements of list A in an increasing order such that my list B should also be changed according to list A. The node no list is given below.
<...
2
votes
2answers
105 views
Using iterative functions to specifically sort a list
The following code sort the list li in a such way that consecutive terms $t_n,t_{n+1}$ are of the from ...{x_,y_}, {y_,z_}.... i....
2
votes
2answers
67 views
Sorting a list of pairs so that the larger number in the pair appears first [closed]
Imagine I have this data.
I want to sort it so that it takes the form:
{{<larger>, <smaller>}, {<larger>, <smaller>}, ...},
Any help ...
1
vote
0answers
34 views
How do i sort a list of lists of vector pairs? [closed]
My problem is probably not so difficult but I could not find a solution myself.
I am doing computations with 4 dimensional vectors, they represent the vertices of a polytope. So the order of the ...
1
vote
4answers
106 views
Sorting a function
So I have a function f[x : {{_, _} ...}] := f /@ x; f[a_,b_]=:a+b. I can input f[{1,2},{2,0},{3,4}] and get ...
1
vote
1answer
55 views
Sorting the eigensystem of a symbolic matrix
My symbolic matrix $A$ reads
\begin{equation*}
\left(
\begin{array}{ccc}
a \left(x^2+y^2+z^2\right) & b y z+i v x & -i v y \\
b y z-i v x & a \left(x^2+y^2+z^2\right) & b x y+i v z \\...
1
vote
1answer
88 views
Nonrepetitive representation of a group of lists (with sharing members)
Background:
Lets first construct a square graph (the ha and second points define to implement periodic boundary condition):
...
7
votes
2answers
238 views
List of tuples without duplicates & repeated values [duplicate]
Given some number nand set of values vals, I want to obtain all the tuples/permutations of size ...
0
votes
0answers
42 views
Confusion about the sorting function
The following one-dimensional array can be sorted well:
Sort[{Infinity, 10, 2, 1, -4}, #1 < #2 &]
But the following two-dimensional array cannot sort the <...
asked Aug 7 '20 at 7:28
A little mouse on the pampas
4,3582 gold badges9 silver badges27 bronze badges
3
votes
3answers
107 views
1
vote
1answer
60 views
Sort a nested Association by another Association
I have a nested association of numerous pixel values sorted by sample date (e.g. 20190422C) and futher by a strain percentage (e.g. 0, 30, 50).
I want to sort it even further using and Association of ...
4
votes
3answers
108 views
14
votes
3answers
227 views
Ordering Problem With VoronoiMesh
Imagine I want to model 2D cells moving in a tissue. Consider, as an example, Lloyd's relaxation algorithm. Using VoronoiMesh I'm able to mimic some cell movement. ...
8
votes
2answers
331 views
Best way to insert element into an ordered list at the correct position?
Suppose I have an ordered list orderedList and I want to write some code that will involve regularly inserting new elements into ...
0
votes
2answers
27 views
Arranging terms by the values of numerical coefficients
I have a list with elements of the form myList = {c1 F1, c2 F2, c3 F3, ...} where c1, c2, ... are explicitly integers, and ...
0
votes
0answers
60 views
Resorting nested list A according to nested list B
How can sort nested list according to each other? e.g. I have the following list:
...
6
votes
1answer
112 views
How to group together numbers in a list by the value of their tens digit?
The line Table[Prime[n],{n,1000}] produces the list of first 1000 primes. Given this list how can the values be grouped by the values of their tens digit? i.e. how ...
4
votes
1answer
108 views
Sorting exponential numbers
I want to sort some exponential numbers like {2^2,3^3,4^2} and i want The result {2^2,4^2,3^3}.
But Mathematica Sort function apply's the powers in the result and return's {4,16,27}.
How can i get the ...
0
votes
0answers
39 views
How to sort a distance matrix in mathematica
I have the following code which results in the heatmap shown:
...
2
votes
1answer
76 views
Unique matrix ID and fast checking
I have the following problem :
I have a programm which can generate a lot of 3x3 matrices whose elements take integer values in [-3;3], example :{{1,2,3},{-3,0,-2},{1,1,1}}.
Each time my programm ...
2
votes
3answers
123 views
Sorting a sparse matrix so that non-empty rows place on top
I have a $n$ by $2$ matrix that has binary values(0,1) as its entry. For example
m={{1,Null},{Null,0},{Null,Null},{0,0},{1,0},{0,1}}
I want it to be sorted ...
1
vote
1answer
56 views
Sort Stocks by MarketCap
If I correctly understand, here I have all the existing companies listed in every market and identified by each real name:
...
1
vote
0answers
49 views
Why doesn't Sort work in this case ? (Only numerical values)
Context
I want to interpolate a complicated symmetric function f of 2 variables x and y defined by some numerical integral involving Bessel functions. Since computing the integral itself is a bit ...
0
votes
0answers
50 views
Help in modifying my code
In my code, I want to plot (Dis[t]). The problem is some functions containing in the code do not work well if there are variables in the form of symbols, such as "Sort" "NMaximize" functions.
I want ...
0
votes
0answers
29 views
Preventing mathematica from evaluating “Sort” function, except in the case of numerical values
Say I want to sort the eigenvalues E1, E2, and E3 using "Greater" as following:
{EA, EB} = Sort[{Chop[E1], Chop[E2], Chop[E3]}, Greater][[{1, 2}]];
But I want ...
0
votes
0answers
53 views
“Greater” function gives me wrong order
When I try to sort the eigenvalues of the matrix (Rho) the results seems to be in the wrong order
What is wrong with my code?
...
-1
votes
1answer
27 views
Adding up a list of rules
Here's the problem: I take a count of a count, so that I end up with a list in this format:
Table[Counts@Counts@Join[dKm[[i]], Pick[data1, ccKMedoid, i]], {i, 5}]
...
2
votes
1answer
43 views
Does Mathematica have an order relationship for lists, or a general ordering relation?
{1, 2} < {3, 4} doesn't seem to work, but Sort[{{3, 4}, {1, 2}}] yields {{1, 2}, {3, 4}}. ...
6
votes
4answers
226 views
Faster way to find longest chain of inequalities
I have a list of algebraic expression, all variables are positive, some of them have a specific size relationship.
Such as:
$\frac{(a b+a c+b c)^2}{a+b+c}\leq \frac{1}{3} (a+b+c) (a b+a c+b c)\leq \...
0
votes
2answers
33 views
Arrange exceptions in a list by some criteria
I have some dataset, which is supposed to have $30000$ in the last column, and I want to find the elements that break this, and arrange them numerically while mantaining the index. What I'm currently ...
2
votes
0answers
48 views
SortBy without final cannonical ordering
How can I SortBy a list without final cannonical ordering? E.g. SortBy[{9, 1, 2, 5, 3, 7}, # Boole[# >= 6] & ] returns <...
3
votes
1answer
185 views
Fast way of re-ordering list
I have a list which at each iteration of my algorithm is being modified. What I want to do is to find the elements that satisfy certain criterion (below it's simply being above the neighborhood ...
4
votes
1answer
299 views
How can we compare two strings?
In Python, you can do this:
"ab" > "ac"
which returns False.
In Mathematica, it doesn't evaluate.
But why? These are ...
6
votes
2answers
109 views
How to group points based on mesh primitive membership
As a simple example of what I want to do, let's say I have a Voronoi mesh in a $10\times10$ area with $10$ random "seed points":
...
8
votes
4answers
321 views
SortBy first element then second element, and so on?
SortBy can sort list by first element easily like so:
SortBy[{{1, 6}, {1, 2, 8}, {2}}, First]
and the result is:
{{1, 6}, {...
4
votes
2answers
270 views
1
vote
1answer
36 views
Pick out two related elements from a list using criterion
Suppose I have a list:
$lst= \{\{k_1, g_1\},\{k_2,g_2\},...,\{k_{max},g_{max}\},...,\{k_n,g_n\}\}$
Here $\{k_{max},g_{max}\}$ is a special element, in which $g_{max}$ is the maximum of all $g_{i}$
...
2
votes
1answer
49 views
Matching list of eigenvalues and eigenvectors and removing negative values [closed]
I Have a matrix M (14x14) dimension in terms of variable k. Due to the complexity I wish to diagonalize M numerically as I can't symbolically.
...
3
votes
2answers
81 views
How to separate and re-order a list of points?
Suppose that we have a list of points. By plotting them we find two curves but the points are in a sequence of first fixing $x$ and then increasing $y$, next fixing $x+dx$ and then increasing $y$ and ...
