Reduce refers to the operation, where a array of items is reduced to a single value. Use with language tag like [c++], [google-sheets-formula]. Do NOT use alone.
Questions tagged [reduce]
3548 questions
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4 answers
Convert array of objects to array of arrays (by attribute)
I want transform my array to array of arrays by attribute "icon".
const array = [
{ icon: true },
{ icon: false },
{ icon: false },
{ icon: true },
{ icon: false }
]
I need:
[[{icon: true}, {icon: false}, {icon: false}], [{{icon:…
user3468894
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One-line generator that acts like reduce but yields all intermediate results
I love how easy it is to implement all kinds of commonly used high-level algorithmic behavior in Python.
I am now looking for an optimal way of implementing recursive sequences or any other kind of generator whose next value depends on O(1) of the…
Domi
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4 answers
Scala .reduce strange behaviour on generic types
I've been wondering, why this piece of code won't compile?
Is there a way in Scala to create method/func that is generic parametrised and allows for such operation like 'reduce'.
Is this behaviour having anything in common with type erasure or is…
dreamsComeTrue
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4 answers
ES6 Sum by object property in an array
I am trying to sum the unit value by date, and create a new array where there are no duplicate dates. For example, I want to calculate the total of 2015-12-04 00:01:00. This date has occurred 2 times in the following data, its value is 5 and 6,…
Anson C
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3 answers
Reduce an array into a single integer causes type error
I'm trying to take an array of Pairs(StartTime:Int, EndTime:Int) and reduce them to the accumulation of time for each session.
fun main() {
val sessionsInSecond = listOf>(Pair(10,12), Pair(10,15))
val timeSpan: Int =…
Joel Broström
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1 answer
Merge data frames based on column with different rows
I have multiple csv files that I read into individual data frames based on their name in the directory, like so
# ask user for path
path = input('Enter the path for the csv files: ')
os.chdir(path)
# loop over filenames and read into individual…
n8-da-gr8
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5 answers
How would I transform this array of arrays into an array of objects using a functional style in JavaScript?
I'd appreciate some help in this problem I'm trying to solve in a particular way. I'm trying to use forEach() and reduce() to transform a dataset from one format - an array of arrays - into another - an array of objects. I know that arr.forEach(i)…
tedico
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1
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2 answers
Reducing by (K,V) pairs and sort by V
I'm super new to pyspark and RDDs. Apologies if this question is very rudimentary.
I have mapped and cleaned by data using the following code:
delay = datasplit.map(lambda x: ((x[33], x[8], x[9]))).filter(lambda x: x[0]!= u'0.00').filter(lambda x:…
A Dolegowski
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In Woo I need real stock levels to decrease when order is created and don't decrease until order cancel
I need a product stock to decrease immediately on order creation and it should not increase unless the order is cancelled (it should also not decrease a second time upon payment successful or any other switch).
My problem is I want to use my…
Cranmoot
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4 answers
add up numbers in array
I've been following this post but I cannot get my array to add up all numbers in my array.
I use this:
var array_new = [$(".rightcell.emphasize").text().split('€')];
to give me this array:
array_new: ,102.80,192.60,22.16
then I do this:
var…
artworkjpm
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2 answers
Get nested object values and put it on a table header
In the following stackblitz sample. I have the following data:
My table is displaying what I want, As you can see inside the timeline object the "start" values are exactly the same as the ones inside the aval array
Therefore, is there anyway I can…
brohymn
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1 answer
For loop slower than reduce?
I'm getting very strange timings from this code. At times the for loop runs much more slowly.
var len = 8e6
function *rands(){
for(let i =0; i < len; i++)
yield Math.random()
}
var add = (a,b) => a + b
var arr = new…
Truman Purnell
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1 answer
Is it possible to find the supremum norm of a vector applying Open MPI Reduce operation with Op MPI.MAX/ MAXLOC
I need to find the supremum norm (maximal element of vector) of a vector. I can implement is using norm function of linear algebra library of mpi4py.
x = np.linspace(0, 100, n)
mxnorm_x = norm(x, np.inf)
print "mxnorm-x", mxnorm_x
However, I need…
mirzapinku
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how to reduceByKey on a transformation of the key and return the whole record
I have an RDD with [String, Int] type columns, respectively.
RDD values are like :
("A x",3)
("A y",4)
("A z",1)
("B y",2)
("C w",5)
("C y",2)
("E x",1)
("E z",3)
What I want to accomplish is to get an RDD like this (String,Int):
("A y",4) #among…
Jimmo
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4 answers
Reduce Multiple Objects into One
Let's say I have an array of objects:
[
{
category: 'Category A',
max: 10,
min: 12
},
{
category: 'Category B',
max: 2,
min: 1
},
{
category: 'Category C',
max:…
LuisDemn
- 19
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