Cumsum is a MatLab, NumPy, Pandas and R function that returns the cumulative sum along different dimensions of an array.
Cumsum is a MatLab, NumPy, Pandas and R function that returns the cumulative sum along different dimensions of an array.
Questions tagged [cumsum]
799 questions
4
votes
1 answer
"Cumulative difference" function in R
Is there a pre-existing function to calculate the cumulative difference between consequtive values?
Context: this is to estimate the change in altitude that a person has to undergo in both directions on a journey generated by…
RobinLovelace
- 4,799
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- 40
4
votes
2 answers
Reversing cumulative sum to determine actuals in R
I have a df where each row is the cumulative sum of the row above it. Is there a way to derive the original values from this df?
X1 X2
1 1 5
2 3 9
3 6 12
4 10 14
5 15 15
Desired output:
X1 X2
1 1 5
2 2 4
3 3 3
4 4 2
5 5 …
Chris S
- 55
- 3
3
votes
2 answers
Fill gaps between 1's in Pandas dataframe column with increment values that reset when next 1 is reached
Apparently this is a more complicated problem than I thought.
All I want to do is fill the zeros with ++1 increments until the next 1
My dataset is 1m+ rows, so I'm trying to vectorize this operation if possible.
Here's a sample column:
# Define the…
nborel
- 33
- 4
3
votes
2 answers
Keep row as soon as cumulative value reaches a certain threshold R
I have a dataframe where I would like to keep a row as soon as the cumulative value of a column reaches a certain level. The dataset could look like this:
set.seed(0)
n <- 10
dat <- data.frame(id=1:n,
…
reinoud
- 63
- 6
3
votes
1 answer
Binary search tree cumsum
Problem: Given a binary search tree in which the keys are numbers, we'll define the operation 'cumsum' ( shorthand for cumulative sum ) that switches the key of every node in the tree with the sum of all the keys that are smaller or equal to it.
For…
jacob12
- 173
- 8
3
votes
1 answer
Cumsum column while skipping rows or setting fixed values on a condition based on the result of the actual cumsum
I'm trying to find a vectorized solution in pandas that is quite common in spreadsheets which is to cumsum while skipping or setting fixed values on a condition based on the result of the actual cumsum. I have the following:
A
1 0
2 -1
3 …
Gus
- 193
- 9
3
votes
1 answer
Matlab find() function in R
I am trying to convert some Matlab code into R. The code looks something like this:
u= [.4 .5 .1;
.2 .4 .4;
.4 .1 .5]
z= find(cumsum(u)>= rand,1)
OUTPUT: e.g. z = 3
The mathematical background is described like this (from a math tut.…
Steffen Schwerdtfeger
- 109
- 8
3
votes
3 answers
Cumulative sum in pandas starting with a zero and ending with the sum of all but the last entry respecting groups
In the dataframe below, I want to create a new column C which will be the cumulative sum of B for each group in the A column, but these sums must start at zero and only add the values until the penultimate entry for that group.
A B
0 1 5
1 1 6
2 2…
William M.
- 235
- 1
- 9
3
votes
1 answer
Pandas cumulative sum depending on other columns value
I have a Dataset like this
Date Runner Group distance [km]
2021-01-01 Joe 1 7
2021-01-02 Jack 1 6
2021-01-03 Jess 1 9
2021-01-01 Paul 2 11
2021-01-02 …
Peter
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- 1
- 1
- 5
3
votes
5 answers
Groupby of different columns with different aggreagation with cumsum with another dataset
I have a dataframe sorted by date and time as :
df1:
ID Date A_sum A_count B_sum B_count A_last B_last
abc 01/jan 26 2 25 2 0 0
xyz 01/jan 54 3 45 3 4 6
df2:
ID …
naina
- 303
- 3
- 14
3
votes
1 answer
Calculating sum of up to the current row in pandas while iterating on each row in a time series data
Suppose I have the following code that calculates how many products I can purchase given my budget-
import math
import pandas as pd
data = [['2021-01-02', 5.5], ['2021-02-02', 10.5], ['2021-03-02', 15.0], ['2021-04-02', 20.0]]
df =…
user1330974
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- 60
3
votes
3 answers
Acumulative sum in R
I have data containing columns x and lx, I want to get cumulative sum on lx basis. My data is like:
x
l(x)
20
100.000
21
99.644
22
99.286
23
98.925
24
98.561
25
98.195
26
97.829
and I want to get output like…
Manuel Rodríguez
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- 3
3
votes
1 answer
groupby cumsum sorted dataframe
I want to group a dataframe by a column then apply a cumsum over the other ordered by the first column descending
df1:
id PRICE DEMAND
0 120 10
1 232 2
2 120 3
3 232 8
4 323 5
5 323 6
6 …
user3379546
- 77
- 7
3
votes
1 answer
Cumulative Sum of Grouped Strings in Pandas
I have a pandas data frame that I want to group by two columns and then return the cumulative sum of a third column of strings as a list within one of these groups.
Example:
Year Bucket Name
2000 1 A
2001 1 B
2003 1 C
2000 …
JBN
- 67
- 4
3
votes
2 answers
Rolling cumsum in data.table
Trying to get (reverse) cumulative sums in a moving window by group in data.table. For example, from the following data I'd like to get those values in the "roll_cumsum" column:
dt = data.table()
dt[, a := seq(1, 10, 1)]
dt[, group := rep(1:2, each…
jayc
- 329
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