The differences between the elements in a vector or a matrix.

Syntax

d = Diff(m,n,dim)

Argument

Name

Description

m

A data vector or matrix. It must have at least 2 elements.

n

(optional)

The number of iterative differences to be computed. The default is 1.

dim

(optional)

The direction along which to take differences. For differences along columns, dim = 1. For differences along rows, dim = 2. If m is a matrix, dim defaults to 1. If m is a vector and dim is omitted, the differences are taken along the vector regardless of its orientation.

Output

Name

Description

d

The vector of differences between the elements of m.

Length(d) =  Length(m) - n.

Example 1

Find the vector of differences.

Syntax

D = Diff([1,2,4,7,11])

Result

D = 1  2  3  4

Example 2

Find the vector of second differences.

Syntax

D = Diff([1,2,4,7,11], 2)

Result

D = 1  1  1

See Also:

Derivative

Sum