Linked Questions

6
votes
4answers
378 views

Find the identical rows in a matrix [duplicate]

Suppose I have the following matrix: ...
4
votes
6answers
417 views

Randomly distribute numbers to lists

I have 4 empty lists. I would like to randomly distribute numbers from 1 to 10 to these 4 empty lists. How can I add integers to lists randomly? For example: ...
4
votes
2answers
208 views

position of intersection of two lists

I have the two lists: ...
3
votes
3answers
146 views

How to get a description of the positions of similar elements in a list

I want to find a function F to represent the positions of identical elements in a list, which means, for example: ...
5
votes
2answers
146 views

Determining lists with equal elements in the same position

I would like to define a function with the following properties: Given a list of equal length sub-lists ls={{a,a,a},{a,b,a},{a,b,c}}; Define a function ...
10
votes
7answers
764 views

intersection between two 2D arrays with labeled data is slow

Here is how to Generate data the function is below with two images to generate data img1 img2 ...
8
votes
2answers
302 views

Interpolating four-dimensional data

In this case it is not easy to work with a MWE, so I shall use the actual data which contain initial conditions $(x,y,p_x,p_y)$. Let's see how the data look on the $(x,y)$ plane ...
7
votes
4answers
187 views

Summing elements in a list by groups indicated by a list of indices

I have two lists, one containing values, the other indices. Now I want to accumulate the values that have the same corresponding index. So for example: ...
1
vote
4answers
267 views

Using Select in Subsets [duplicate]

I have a list: list = {{7, 6, 14, 14, 4}, {4, 9, 8, 11, 14}, {20, 12, 12, 11, 3}, {7, 4, 11, 7, 20}, {2, 13, 17, 11, 19}} I did a test to identify where ...
25
votes
5answers
820 views

Partitioning a list when the cumulative sum exceeds 1

I have a long list of say 1 million Uniform(0,1) random numbers, such as: dat = {0.71, 0.685, 0.16, 0.82, 0.73, 0.44, 0.89, 0.02, 0.47, 0.65} I want to ...
11
votes
9answers
461 views

Positions of elements in the initial flattened list in a split list

Say, we have a list: m1 = {2, 2, 7, 0, 7, 7, 2, 2, 2} It can be split easily: ...
18
votes
5answers
877 views

Easiest/most efficient way to delete duplicates from one list at the positions of another?

This question is somewhat related to How to efficiently find positions of duplicates? , although I'm interested in something a little bit simpler since I'm not really interested in a list of all the ...
16
votes
6answers
532 views

Pick elements from list “separately”

I have the following list I want to pick elements from: mylist = {1, 5, 7, 3, 4, 7, 2, 9, 9, 1, 10, 12, 2, 64, 34, 64} I have another list with 0's and 1's which ...
12
votes
6answers
650 views

How do I prune a list of pairs of numbers so that each number occurs on only one pair?

How do I select only the first pair of numbers in which a number occurs from a list of pairs of numbers? For example, I have ...
13
votes
5answers
2k views

Match opening and closing parentheses?

Suppose I have a List of the form: lst={"(", "(", "(", ")", "(", ")", ")", ")"} By running ...

15 30 50 per page