Linked Questions

535
votes
19answers
135k views

Where can I find examples of good Mathematica programming practice?

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ...
36
votes
0answers
871 views

Performance problems in new Sequence functions

The new-in-10.1 Sequence* family of functions should provide newly optimized methods for handling sequence problems. Happily in some cases they do! For example ...
19
votes
9answers
2k views

How to replace an element in a list based on the value of the next element?

I use Mathematica a little bit. I try to understand it, but it is hard I have a list of 5 numbers selected randomly from 0 and -1. I have to replace a 0 with a 1 when the 0 is followed by -1. My ...
10
votes
4answers
843 views

Find positions of items in a list based on neighbours

How can I select items from a list where the selection criterion depends on the neighbouring items? For example select all indices where a change has occurred with respect to the previous element in ...
10
votes
7answers
705 views

Counting subsequences (i.e., patterns) within a list?

I would like to count the number of subsequences in list. Say I have data given by: data = {1, 1, 1, 2, 1, 2, 2, 2, 1, 2, 1}; I would like to count the number ...
9
votes
10answers
513 views

Locate Start and End Positions of Repeated Sequences in a list

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9
votes
7answers
572 views

Extracting sequences from a list?

Suppose I have a list of arbitrary length like {1, 2, 3, "Open", 3, 2, "Close", 9, 3, 4, "Open", 1, 0, "Close", 3, 5} and I am trying to extract the sequences ...
8
votes
4answers
736 views

How to locate a list within a list?

for example f[{1,2,3,4},{2,3}]=True, f[{1,2,3,4},{2,3,4}]=True but f[{1,2,3,4},{2,4}]=False. ...
8
votes
5answers
1k views

Compare 2 lists

I want to compare 2 lists. One is very large and I need to compare many times. Lets say Length[list1] < Length[list2]. I need to know how many times ...
8
votes
4answers
330 views

Check in a series if there exists adjacent values with less than a certain number of missing values

I'm working with a large number of series of different experiments, where there exist a lot of experiments where there are no entries. I now want to draw a sample where there should exist at least ...
6
votes
1answer
157 views

Find subsequence A in sequence B A007908 - OEIS

I have sequence A as A007908 - OEIS and pattern B which is a sub-sequence of that sequence A. I need to find index of first occurrence of the given pattern. For example pattern ..1010... I've looked ...
5
votes
3answers
2k views

position of sequence of elements in list [duplicate]

Possible Duplicate: Finding a subsequence in a list Question The position of {3, 5} is the list {1, 3, 4, 3, 5, 5, 1} is 3. How can such a position be ...