Questions tagged [sorting]
Questions on the sorting/ordering functions of Mathematica (Sort, SortBy, Ordering, etc.).
404
questions
5
votes
2
answers
137
views
Sorting a list by a single particular element in a specified order
I have a list of lists -- a list of sublists -- that I wish to sort in a specified order. The following function, sortBy2ndElement, sorts a list of lists (...
- 9,747
3
votes
2
answers
85
views
Order elements of list according to predefined ordering [closed]
I have quite a lot of sublists of different length whose elements I would like to order according to a specific predefined ordering.
To be explicit: I am given a specific ordering of indices (i,j,k,l,...
- 91
1
vote
2
answers
55
views
Is it possible to prevent two functions from commuting?
I have an expression of the following type:
x f[a] g[b]
where x is a number but f[a] and <...
- 651
6
votes
1
answer
111
views
Sort the nested list by the sublist content; sublists of different lengths
I would like to write the function NewSort function that sorts a list of sorted sublists, basing first on the canonical ordering of subsequent sublist elements. In ...
- 73
3
votes
1
answer
71
views
Basic question Sort criteria
Can you explain the following codes? (output of codes)
I know that
there is the default ordering for any expression in Mathematica
and Sort uses the default ...
- 3,529
2
votes
1
answer
69
views
Cycle symmetric Sort for arguments of a function. Put trace in canonical order
I need a new Sort for the arguments of TR that maintains cyclicity, TR[a,b,c] = TR[b,c,a] = TR[c,a,b]
cyclicSort[TR[b,a,c]]
TR[a,c,b]
...
- 630
7
votes
1
answer
216
views
Ordering Arguments of Antisymmetric Functions in Cyclic Way
I have two functions ang and sqa, each of which take two arguments which must be distinct integers between 1 and 6. For instance I could have ang[2,1] or ...
- 137
3
votes
3
answers
67
views
Sort a list using a scoring list with Switch [duplicate]
I have a minimal working example (MWE) list called listToSort that is a list of string triplets:
...
- 9,747
5
votes
1
answer
135
views
Fail to understand Ordering[], need to get the ranking of elements in a list
Ordering[{2, 1, 6, 4, 7, 10}]
gives me as a result, {2, 1, 4, 3, 5, 6}, which I understand, 10 is the 6th smallest element. However
...
- 121
8
votes
2
answers
303
views
SortBy with a 2nd argument that specifies not to sort the list?
One can specify the second argument of SortBy not to sub-sort ties, i.e. cases that have identical values according to the main sorting function. ...
- 46.2k
0
votes
1
answer
50
views
Sorting a list by increasing order algorythm [closed]
Im new to loops on mathematica,was wondering how could I create a function to loop through a list which finds the index of the smallest value of that list, makes a sublist from index 1 to that ...
- 93
6
votes
3
answers
300
views
How to Partition List into sublists so that it orders down columns when placed into a Grid instead of across rows
Partitioning a List into sub-lists and placing them directly into a Grid orders sub-lists across rows. Is there an idiot-proof built-in function or a simple ...
- 2,337
1
vote
0
answers
32
views
How to create a Sort function that does not differentiate between String rule keys and Symbol rule keys
Im trying to Sort Rule-s according to Key-s (or names) but the normal ...
- 2,337
3
votes
3
answers
211
views
Sorting a list based only on a certain property of the first element of sublists
Suppose I have a list called roster. Each element in roster is a list containing two strings: (i) the species of animal and (ii) ...
- 9,747
0
votes
1
answer
41
views
Sorting a dataset on multiple column
Following an answer provided by kglr in a previous post:
...
- 1,576
0
votes
1
answer
56
views
Sorting a symmetric matrix alphanumerically
NOT related to my related question! (Different problem source)
This time, I want to sort a symmetric matrix M, and it must stay symmetric (i.e. row and col sort is the same). WLOG the diagonal is 0 (...
- 949
1
vote
0
answers
73
views
SortBy the second element in the sublists
Is there a way to sort sublists in a list by the sublists' second element?
For example, if the list is:
...
- 205
3
votes
2
answers
432
views
How can I sort {S1, S15, S19, S2, ...}?
How can I sort this in order from small to large?
Simple Sort doesn't work here.
...
- 2,822
4
votes
4
answers
179
views
Creating a cycle with conditions
I would like to arrange a gift exchange between 5 people, Alice, Bob, Carl, Danny, and Ellen, and I would like the gifts to be passed in a randomly created cycle (B->C->A->D->E->B), for ...
- 782
4
votes
3
answers
296
views
Insert without extra brackets
I have a List1:
{{1, -1.1}, {2, -1}, {3, -0.9}, {4, 0}, {10, -0.4}}
and List2:
{{2, -0.6}, {3, -0.6}}
and I would like insert ...
- 749
0
votes
0
answers
30
views
Using Insert for multiple Manipulations at once [duplicate]
I have a List1:
{{1, -1.1}, {2, -1}, {3, -0.9}, {4, 0}, {5, -0.8}, {6, -0.8}, {7, -0.3}, {8, -0.1}, {9, -0.7}, {10, -0.4}}
and List2:
...
- 749
0
votes
1
answer
49
views
4
votes
3
answers
296
views
How to replace the element in list of list by its ordering index
I have a list of list: res={{9, 1, 5}, {3, 6, 12}}
I want to change it to res={{5, 1, 3}, {2, 4, 6}}
by following their ordering ...
- 95
9
votes
5
answers
333
views
Collect terms with the same denominator
I have an expression
$$\frac{A}{x}+\frac{A_2}{x^2}-\frac{D_2}{x}+\frac{C_2}{x^2}++\frac{F_2}{x^3}+\frac{I_2}{x^2y}+\frac{U_2}{y^2x}+\frac{Z_3}{x^2y}+\frac{J_2}{y^2x}+\cdots$$
and I am looking for a ...
- 219
3
votes
4
answers
182
views
Finding relative ordering of two lists
Suppose you have two lists A and B which are related by a permutation, and have no repeated elements.
Is there a simple and ...
3
votes
2
answers
81
views
Parting a table by second column elements
I have 2 X m table with elements {{x1, y1}, {x2, y2}, .... {xi, yi}, .....{xm, ym}}. It is an experimental data, which can be seen in the attached picture. There is a significant noise and ...
- 1,103
6
votes
4
answers
594
views
Find min and max indices of highest and lowest elements in sorted list
I have a list of integers of the form
...
- 229
1
vote
4
answers
198
views
Counting number of points in fluctuating lines that fall within a circle
I have a list of points pts that fluctuate around some mean line. pts is pre-sorted by the projection of the points onto this ...
- 229
6
votes
1
answer
144
views
Fastest Way to Find nearest indices between two sorted lists
I have a sorted list of floats of length n and an n x n list of lists, where each nested ...
- 229
4
votes
1
answer
80
views
Ordered list of integer vectors
For a given length $n$ and a maximum positive integer value $N$, I'd like to generate a list that contains all $n$-vectors with entries between $-N$ and $N$ (of which there are $(2N+1)^n$. Further, ...
- 153
2
votes
1
answer
89
views
Dropping non-commutative product in the end
Suppose my expressions are given as a combinations of non-commutative products, i.e., $2 X**Y**Z + 3 Y**Z**X$, I want to make this as commutative product and get $5 X**Y**Z$. And want similar things ...
- 437
0
votes
1
answer
75
views
substitution $A \mapsto A + \delta_A$ with some operator $\delta_A$
I want my input letter $A B$ and substitute $A \mapsto A + \delta_A$ and $B \mapsto B+ \delta_B$ so that
\begin{align}
A B + BA \mapsto A B + B A + \delta_A B + \delta_B A
\end{align}
Here $\...
- 437
8
votes
1
answer
156
views
sorting vector elements of a list by certain rules
I want to write code that sorts out a list by some specific rules.
The rules are logically straightforward, but I am having trouble coding it.
This is my input list
...
- 109
0
votes
0
answers
21
views
Collect terms unexpected behaviour with subscripts and different variable names
If I write Collect[x+a+1, x] the output I get is what I expect
1 + a + x
constant terms with respect to ...
- 101
4
votes
2
answers
131
views
Sorting of a list of lists - i.e. list of matrices - what is the order of the sort determined by?
In the documentation we have:
Sort[list] sorts the elements of list into canonical order.
Maybe I am missing something but what does "canonical order" mean for sorting a list of matrices?
...
- 717
4
votes
2
answers
400
views
Sorting a list of "Low", "Medium", "High" into low, medium, high
I have a list with 10.000 entries containing "low", "medium" & "high" data.
It is in random order. How can I sort that to low, medium high?
- 43
4
votes
2
answers
134
views
Extracting the second largest and minimum values, and plot
How to extract the second lowest and the second largest values of each row, and plot them as upper and lower graphs? I try with TakeLargest (or ...
- 173
1
vote
1
answer
60
views
Sorted Tuples without Filtering
Say I have a list $L$ where the elements can be sorted into some canonical order. I want to use Tuples[L,m] but I only want the output lists to be sorted and ...
- 187
4
votes
2
answers
97
views
Tuples which treats re-ordering as equivalent [duplicate]
I would like to define a new function myTuples, that behaves just like Tuples, except that it treats, as with ...
- 1,317
3
votes
1
answer
135
views
Re-sorting higher-order ordinary differential equations
I have some higher-order ordinary differential equations.
Firstly, I want to collect the terms with common factors together. Besides, I want to re-sort the ODE with the highest order term first.
How ...
- 355
1
vote
1
answer
169
views
How to sort a list of strings in alphabetical order? [closed]
I have a list of strings:
listOfStrings = {"dog", "zebra", "donkey", "anteater", "fish"};
How do I sort them in ...
- 431
1
vote
1
answer
68
views
How to sort a "+" sequence and get back a new sequence of "+" sorted? [closed]
How to sort a "+" sequence like
1+5+3+2+4
to get back
1+2+3+4+5
Same sorting problem with polynoms (but I am mainly ...
6
votes
4
answers
205
views
How to order the coordinates generated by ToBoundaryMesh counterclockwise?
The following code works for polygons. A square 4x4 is tried here:
...
1
vote
1
answer
117
views
Sort polynomial by monomial degree [closed]
there is an equation :
z = a^2 + a b + a a' + a a' a'' + a b'
and i want to rearrange the equation by sorting the terms by number of variable multiplication within.
If my English is not well, let me ...
- 61
5
votes
2
answers
235
views
2
votes
2
answers
127
views
Sorting pairs of approximate numbers
In an ideal world I would have:
list1 = {{2, 0}, {2, -1}, {2, 0}, {2, -1}};
Sort[list1]
{{2, -1}, {2, -1}, {2, 0}, {2, 0}}
while in the real world I have:
...
- 291
2
votes
1
answer
348
views
2
votes
1
answer
38
views
Arrange an expression based on variables' names
I have a problem of arranging an expression as shown in the following picture. The first expression exp is derived from other functions and equations. I want to get ...
- 663
1
vote
2
answers
78
views
Arrange an expression based on functions' names
I have a problem of arranging an expression as shown in the following picture. The first expression disorderF is derived from other functions and equations, which ...
- 663
2
votes
2
answers
119
views
For a given set, how to get rid of the some particular set?
Consider the following decomposition list of $\{a1,a2,a3,a4\}$ into three parts as $t$,
t={{{a1, a2}, {a3}, {a4}}, {{a1}, {a2, a3}, {a4}}, {{a1}, {a2}, {a3,
a4}}, {{a1, a2}, {a4}, {a3}}, {{a1}, {a2,
...
- 437