Tagged Questions
2
votes
1answer
61 views
Flat function with repeated sequence
There are functions like Join[ ] that accept a variable number of arguments. Join is a flat function, as the order of arguments ...
4
votes
5answers
197 views
Removing zero values from ordered pairs
I have some processed data, which are basically a collection of ordered pairs in the form:
{{x1, y1}, {x2, y2}, ..., {xn, yn}}
Ordered pairs which have either a ...
8
votes
4answers
272 views
Best way to modify values in a list of rules?
Recently I had to solve a problem similar to this:
Let's say I have a list of list of rules
...
8
votes
5answers
181 views
How can I remove matching sublists from my list?
I want to use DeleteCases (or any appropriate function) to remove elements of a list, which in turn are lists of fixed size. The rule I wish to apply is that any ...
1
vote
2answers
209 views
How to generate patterns by a list of integers
I have a list of integers {3,4,2,2}.
This list will give patterns {x_,_,y_,y_,_,_,z_,z_,w_,w_,x_} and ...
7
votes
1answer
111 views
Transformation rule on a list of non-negative integers
I am trying to create a transformation rule that takes a list of non-negative integer values of any length, finds a non-zero entry in the list, adds 1 to all preceding numbers, subtracts 1 from the ...
4
votes
4answers
186 views
How to pick out the element in a list of lists which satisfies a particular condition?
I have got a list:
...
26
votes
6answers
899 views
Find zero crossing in a list
I'm looking for a function that finds the index of the zero-crossing points of a list. Before I go making my own subroutine to do this, I was wondering if anyone knows of any built-in Mathematica ...
0
votes
1answer
161 views
Count sublists which match pattern
I have a list which looks like this: data={{12,0},{0,0},{20,1},{0,0}, {0,-1}}. Now I would like to count the number of sublists which:
have both slots zero
the ...
9
votes
5answers
675 views
Counting negative values in list
I would like to count the negative values of a list.
My approach was Count[data, -_] which doesn't work.
How can I tell Mathematica to count all numbers with ...
1
vote
2answers
118 views
Using patterns in ReplaceAll to extract elements from tuples at arbitrary depths
Please consider the following:
I need to extract from MyList all last parts of each 3-tuple.
...
12
votes
4answers
234 views
The gap between MapAt and ReplacePart for 2D data tables with headers
Consider a relational table derived from survey data, where each column ("001-01" ...) represents a responder and each row (...
6
votes
3answers
273 views
Specifying string patterns in DeleteCases
It seems that DeleteCases is not compatible with string patterns, at least directly (see, for example, this question). Is this true? If so, why is this the case? ...
4
votes
3answers
171 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 ...
7
votes
1answer
147 views
Built in way to de-list singletons?
Is there a built in method to de-list singleton expressions, like this rule-based solution:
expr_ :> If[Length[expr] == 1, First@expr, expr]
In data ...
7
votes
2answers
225 views
Building a tree
Given a list of word characters, such as this one, I'd like to build a tree, similar to this makeTree function, but with the tree in a different format. So, for an input such as
...
4
votes
4answers
288 views
Creating lists from a string, separating words from numbers
Say I have a string that contains numbers and words, such as this one:
string = "there are 1234 words and numbers 5678 in here $999";
How would I separate the ...
9
votes
4answers
283 views
Using Position (which requires a pattern) in the same manner as Select (which requires a criterion)
I am using Mathematica7. I have a list of lists (creatively named list in the following sample code) containing data. I would like to find the positions of the ...
2
votes
2answers
175 views
Pattern test for variables during function definition
I am having a problem with pattern testing on variables during function definition
...
15
votes
4answers
341 views
Splitting a list
Please consider the following list:
data={1, 0, 0, 0, 2, 5, 2, 3, 0, 0, 3};
Now I would like to split the list into 0-sequences and Not-0-sequences as following:
...
11
votes
3answers
274 views
Delete duplicates in a list, depending on the sequence of numbers
Below, list is a representative sample of my list, which contains lists of integers. I would like to be able to input:
...
2
votes
2answers
76 views
Using FreeQ with implicit functions
In Mathematica 7, I want to determine whether a list of free of numbers greater than 1 or not. It seems like using FreeQ would be a concise way to do this:
...
9
votes
3answers
192 views
Splitting a list in which figures vary from negative to positive
Consider the following list:
data={4078, 256, -1266, -388, 1290, 1368, 1446, 1524, 2};
I would like to split any kind of such list always, when figures turn form ...
4
votes
1answer
182 views
4
votes
2answers
248 views
Why can't NumberQ be used as the head of a pattern?
Consider the following:
list={1/First[{}], 1, 2, 1/First[{}], 3};
DeleteCases[list,_NumberQ]
I wanted to remove all cases, which did not match ...
4
votes
1answer
250 views
Path queries for tree-structured data
Can anyone suggest documentation or tutorials for developing path queries and indices for (XML-like) tree-structured data?
Suppose data is organized hierarchically in key->value pairs, eg:
...
8
votes
4answers
218 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 ...
