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Symbolic cumulative sum

Create a vector and find the cumulative sum of its elements.

V = 1./factorial(sym([1:5])) sum_V = cumsum(V)

V = [ 1, 1/2, 1/6, 1/24, 1/120] sum_V = [ 1, 3/2, 5/3, 41/24, 103/60]

Create matrix a 4-by-4 symbolic matrix `A`

all
elements of which equal 1.

A = sym(ones(4,4))

A = [ 1, 1, 1, 1] [ 1, 1, 1, 1] [ 1, 1, 1, 1] [ 1, 1, 1, 1]

Compute the cumulative sum of elements of `A`

.
By default, `cumsum`

returns the cumulative sum
of each column.

sumA = cumsum(A)

sumA = [ 1, 1, 1, 1] [ 2, 2, 2, 2] [ 3, 3, 3, 3] [ 4, 4, 4, 4]

Create matrix a 4-by-4 symbolic matrix `A`

all
elements of which equal 1.

A = sym(ones(4,4))

A = [ 1, 1, 1, 1] [ 1, 1, 1, 1] [ 1, 1, 1, 1] [ 1, 1, 1, 1]

Compute the cumulative sum of each row of the matrix `A`

.

sumA = cumsum(A,2)

sumA = [ 1, 2, 3, 4] [ 1, 2, 3, 4] [ 1, 2, 3, 4] [ 1, 2, 3, 4]

Create matrix a 4-by-4 symbolic matrix, all elements of which equal 1.

A = sym(ones(4,4))

A = [ 1, 1, 1, 1] [ 1, 1, 1, 1] [ 1, 1, 1, 1] [ 1, 1, 1, 1]

Calculate the cumulative sum along the columns in both directions.
Specify the `'reverse'`

option to work from right
to left in each row.

columnsDirect = cumsum(A) columnsReverse = cumsum(A,'reverse')

columnsDirect = [ 1, 1, 1, 1] [ 2, 2, 2, 2] [ 3, 3, 3, 3] [ 4, 4, 4, 4] columnsReverse = [ 4, 4, 4, 4] [ 3, 3, 3, 3] [ 2, 2, 2, 2] [ 1, 1, 1, 1]

Calculate the cumulative sum along the rows in both directions.
Specify the `'reverse'`

option to work from right
to left in each row.

rowsDirect = cumsum(A,2) rowsReverse = cumsum(A,2,'reverse')

rowsDirect = [ 1, 2, 3, 4] [ 1, 2, 3, 4] [ 1, 2, 3, 4] [ 1, 2, 3, 4] rowsReverse = [ 4, 3, 2, 1] [ 4, 3, 2, 1] [ 4, 3, 2, 1] [ 4, 3, 2, 1]

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