seqperiod

Compute period of sequence

Syntax

p = seqperiod(x)
[p,num] = seqperiod(x)


Description

p = seqperiod(x) returns the integer p that corresponds to the period of the sequence in a vector x. The period p is computed as the minimum length of a subsequence x(1:p) of x that repeats itself continuously every p samples in x. The length of x does not have to be a multiple of p, so that an incomplete repetition is permitted at the end of x. If the sequence x is not periodic, then p = length(x).

• If x is a matrix, then seqperiod checks for periodicity along each column of x. The resulting output p is a row vector with the same number of columns as x.

• If x is a multidimensional array, then seqperiod checks for periodicity along the first nonsingleton dimension of x. In this case:

  • p is a multidimensional array of integers with a leading singleton dimension.

  • The lengths of the remaining dimensions of p correspond to those of the dimensions of x after the first nonsingleton one.

[p,num] = seqperiod(x) also returns the number num of repetitions of x(1:p) in x. num might not be an integer.

Examples

Multichannel Signal Periods

Generate a multichannel signal and determine the period of each column.

x = [4 0 1 6; 
     2 0 2 7; 
     4 0 1 5; 
     2 0 5 6];

p = seqperiod(x)

p = 1×4

     2     1     4     3

The first column of x has period 2. The second column of x has period 1. The third column of x is not periodic, so p(3) is just the number of rows of x. The fourth column of x has period 3, although the second repetition of the periodic sequence is incomplete.

Introduced before R2006a

×

Open Example

A modified version of this example exists on your system. Do you want to open this version instead?

No, overwrite the modified version Yes