seqivardur {TraMineR} | R Documentation |

## Variance of spell durations in individual sequences

### Description

Variance of spell durations of individual state sequences.

### Usage

```
seqivardur(seqdata, type=1, with.missing=FALSE)
## S3 method for class 'seqivardur'
print(x, stat='var', ...)
```

### Arguments

`seqdata` |
a state sequence object ( |

`type` |
either 1 or 2. The default |

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

`x` |
an outcome of |

`stat` |
string or vector of strings. Duration statistic to be printed. Either |

`...` |
further arguments such as |

### Details

The returned variance is a population variance, i.e. the sum of squares divided by the number of terms.

When `type=1`

, this is the variance of the observed spells in the sequence. When `type=2`

, in addition to the observed spells one spell of length 0 is considered for each non-visited state. The mean duration is computed the same way.

### Value

A numeric vector with the variance of spell duration of each sequence.

The returned object has two attributes:

`vmax` |
the maximum value that the variance of each sequence could reach given its number of spells. |

`meand` |
the mean spell duration of each sequence. |

### Author(s)

Gilbert Ritschard

### References

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

### See Also

### Examples

```
sq.dat <- c('AAAA','AAAC','ABC','ABAA','AC')
sq <- seqdef(seqdecomp(sq.dat, sep=''), right=NA)
seqivardur(sq, type=1)
seqivardur(sq, type=1, with.missing=TRUE)
vd2 <- seqivardur(sq, type=2)
print(vd2, stat='all')
vd2m <- seqivardur(sq, type=2, with.missing=TRUE)
print(vd2m, stat=c('var','vmax'))
```

*TraMineR*version 2.2-10 Index]