Flattening refers to either reducing a multi-dimensional array to a single dimension or to reducing a class and class methods to handle based function calls.
Questions tagged [flatten]
1554 questions
41
votes
6 answers
Un-optioning an optioned Option
Say I have a val s: Option[Option[String]]. It can thus have the following values:
Some(Some("foo"))
Some(None)
None
I want to reduce it so that the first becomes Some("foo") while the two others become None. Obviously there are many ways to…
Knut Arne Vedaa
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41
votes
2 answers
Flattening an Iterable> in Guava
Is there a flatten method in Guava - or an easy way to convert an Iterable> to an Iterable?
I have a Multimap [sourceMultimap] and I want to return all values where the key matches some predicate [keyPredicate]. So at the moment…
Andy Whitfield
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41
votes
6 answers
Scala - convert List of Lists into a single List: List[List[A]] to List[A]
What's the best way to convert a List of Lists in scala (2.9)?
I have a list:
List[List[A]]
which I want to convert into
List[A]
How can that be achieved recursively? Or is there any other better way?
A Far
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40
votes
2 answers
Python list comprehension, unpacking and multiple operations
I want to unpack the tuples I create by doing the following so he the result is just one simple list. I can get the desired result in 2-3 lines but surely there is a oneliner list.comp?
>>> x = range(10)
>>> y = [(i,j**2) for i,j in zip(x,x)]
>>>…
arynaq
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38
votes
1 answer
How to flatten a List of Futures in Scala
I want to take this val:
val f = List(Future(1), Future(2), Future(3))
Perform some operation on it (I was thinking flatten)
f.flatten
And get this result
scala> f.flatten = List(1,2,3)
If the flatten method isn't appropriate here, that's fine. …
mljohns89
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35
votes
8 answers
Convert array of single-element arrays to a one-dimensional array
I have this kind of an array containing single-element arrays:
$array = [[88868], [88867], [88869], [88870]];
I need to convert this to one dimensional array.
Desired output:
[88868, 88867, 88869, 88870]
Is there any built-in/native PHP…
DEVOPS
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33
votes
2 answers
Remove names from named vector and get only the values
I have a vector like below
tmp <- c(a=1, b=2, c=3)
a b c
1 2 3
I want to flatten this vector to get only 1, 2, 3.
I tried unlist(tmp) but it still gives me the same result.
How to achieve that efficiently?
sertsedat
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33
votes
5 answers
Julia: Flattening array of array/tuples
In Julia vec reshapes multidimensional arrays into one-dimension arrays.
However it doesn't work for arrays of arrays or arrays of tuples.
A part from using array comprehension, is there another way to flatten arrays of arrays/tuples? Or arrays of…
Pigna
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33
votes
11 answers
How to Serialize Binary Tree
I went to an interview today where I was asked to serialize a binary tree. I implemented an array-based approach where the children of node i (numbering in level-order traversal) were at the 2*i index for the left child and 2*i + 1 for the right…
worker1138
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32
votes
5 answers
Flatten multidimensional array concatenating keys
Possible Duplicate:
PHP convert nested array to single array while concatenating keys?
Get array's key recursively and create underscore seperated string
Please, read the whole question before answering.
I have this multidimensional array:
$data…
J. Bruni
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32
votes
8 answers
A better way to use AutoMapper to flatten nested objects?
I have been flattening domain objects into DTOs as shown in the example below:
public class Root
{
public string AParentProperty { get; set; }
public Nested TheNestedClass { get; set; }
}
public class Nested
{
public string…
John
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32
votes
4 answers
how to do a "flat push" in javascript?
I want to push all individual elements of a source array onto a target array,
target.push(source);
puts just source's reference on the target list.
In stead I want to do:
for (i = 0; i < source.length; i++) {
target.push(source[i]);
}
Is there…
dr jerry
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30
votes
7 answers
Flatten a list in Prolog
I've only been working with Prolog for a couple days. I understand some things but this is really confusing me.
I'm suppose to write a function that takes a list and flattens it.
?- flatten([a,[b,c],[[d],[],[e]]],Xs).
Xs = [a,b,c,d,e]. …
ToastyMallows
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28
votes
4 answers
Convert 2 dimensional array
What is selectMany.ToArray() method? Is it a built in method in C#?
I need to convert two dimensional array to one dimensional array.
Manoj
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28
votes
7 answers
How to flatten a tuple in python
I have the following element of a list, and the list is 100 elements long.
[(50, (2.7387451803816479e-13, 219))]
How do I convert each element to look like this?
[(50, 2.7387451803816479e-13, 219)]
olliepower
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