Property | Value |
---|---|
Hex Value | $BB29 |
Categories | |
Localizations |
|
cumSum(
Overview
Returns a list of the cumulative sums of the elements in list
, starting with the first element.
Availability: Token available everywhere.
Syntax
cumSum(list)
Arguments
Name | Type | Optional |
---|---|---|
list | list |
Location
2nd, list, OPS
, 6:cumSum(
Overview
Returns a matrix of the cumulative sums of matrix
elements. Each element in the returned matrix is a cumulative sum of a matrix
column from top to bottom.
Availability: Token available everywhere.
Syntax
cumSum(matrix)
Arguments
Name | Type | Optional |
---|---|---|
matrix | matrix |
Location
2nd, matrix, MATH
, 0:cumSum(
Description
cumSum( calculates the cumulative sums of a list, or of the columns of a matrix, and outputs them in a new list or matrix variable.
For a list, this means that the Nth element of the result is the sum of the first N elements of the list:
cumSum({1,3,5,7,9})
{1 4 9 16 25}
For a matrix, cumSum( is applied to each column in the same way as it would be for a list (but numbers in different columns are never added):
[[0,1,1][0,1,3][0,1,5][0,1,7]]
[[0 1 1]
[0 1 3]
[0 1 5]
[0 1 7]]
cumSum(Ans)
[[0 1 1]
[0 2 4]
[0 3 9]
[0 4 16]]
Advanced Uses
The ΔList( command is very nearly the inverse of the cumSum( command - it calculates the differences between consecutive elements. For any list, ΔList(cumSum(list)) will return the same list, but without its first element:
ΔList(cumSum({1,2,3,4,5,6,7}))
{2 3 4 5 6 7}
Removing the first element would otherwise be a difficult procedure involving the seq( command, so this is a useful trick to know.
For a matrix, if you want to sum up the rows instead of the columns, use the T (transpose) command.
Related Commands
Source: parts of this page were written by the following TI|BD contributors: DarkerLine, GoVegan, Myles_Zadok.
History
Calculator | OS Version | Description |
---|---|---|
TI-83 | 0.01013 | Added |