seqivolatility {TraMineR} | R Documentation |

## Volatility of individual state sequences

### Description

Returns Brzinsky-Fay's objective volatility of each sequence.

### Usage

```
seqivolatility(seqdata, w=.5, with.missing=FALSE, adjust=TRUE)
```

### Arguments

`seqdata` |
a state sequence object ( |

`adjust` |
Logical. Should the indicator be adjusted such that it can reach its bounds 0 and 1. Deafult is |

`w` |
Real in the range [0, 1]. Default is 0.5. Weight given to the proportion of states visited (see Details). |

`with.missing` |
Logical: should non-void missing values be treated as a regular state? If |

### Details

The (objective) volatility is the weighted average between the proportion `pvisited`

of states visited and the frequency `ftrans`

of transitions (state changes). Formally,

`volatility = w \cdot pvisited + (1-w) \cdot ftrans`

The proportion of states visited is computed as `(visited - 1)/(|a| - 1`

) when `adjsut=TRUE`

and as `visited / |a|`

when `adjsut=FALSE`

. Here, `visited`

is the number of states visited and `|a|`

the size of the alphabet.

The frequency of transition is `ftrans = \frac{transn}{max.transn}`

where
`transn`

is the number of transitions (state changes) within the sequence, and `max.transn`

the maximum possible transitions in the sequence.

For the normative volatility, see `seqipos`

. For alternative measures of sequence complexity see `seqST`

, `seqici`

, `seqindic`

.

### Value

A numeric vector with the volatility of each sequence.

### Author(s)

Gilbert Ritschard

### References

Brzinsky-Fay, C. Unused Resources: Sequence and Trajectory Indicators. International Symposium on Sequence Analysis and Related Methods, Monte Verita, TI, Switzerland, Oct 10-11, 2018

Ritschard, G. (2023), "Measuring the nature of individual sequences", *Sociological Methods and Research*, 52(4), 2016-2049. doi:10.1177/00491241211036156.

### See Also

### Examples

```
data(ex1)
sx <- seqdef(ex1[,1:13], right="DEL")
seqivolatility(sx)
seqivolatility(sx, adjust=FALSE)
seqivolatility(sx, with.missing=TRUE)
seqivolatility(sx, w=.7, with.missing=TRUE)
```

*TraMineR*version 2.2-10 Index]