# Opal 2.7

Multilines

## Objectives

- Import time series
- Handle longitudinal data
- Export repeatable variables in a analysis-ready format

## Multilines Import

Import from data sources in tabular format (CSV, SPSS, SQL) with multiple rows per entity

ID | A | B |
---|---|---|

1 | a | 1 |

1 | b | 2 |

2 | a | 3 |

2 | c | 1 |

## Internal Representation

- Entity IDs are unique
- Variables are "repeatables"
- Values are "sequences" in occurrence groups

ID | A | B |
---|---|---|

1 | a b |
1 2 |

2 | a c |
3 1 |

## Longitudinal Data

- Same set of variables
- Different Data Collection Events

ID | A | B |
---|---|---|

1 | a | 1 |

2 | a | 3 |

ID | A | B |
---|---|---|

1 | b | 2 |

2 | c | 1 |

T1

T2

## Longitudinal Data

- View to merge events

ID | A | B | Event |
---|---|---|---|

1 | a b |
1 2 |
T1 T2 |

2 | a c |
3 1 |
T1 T2 |

View of T1 + T2

## Longitudinal Data

- View to merge events

ID | A | B | Event |
---|---|---|---|

1 | a b b |
1 2 1 |
T1 T2 T3 |

2 | a c |
3 1 |
T1 T2 T3 |

3 |
c |
3 |
T1 T2 T3 |

View of T1 + T2 + T3

## Repeatables Mix

- Mix of repeatable and not repeatable variables
- Different occurrence groups

ID | A | B | G | C | D |
---|---|---|---|---|---|

1 | a b |
1 2 |
M | x y z |
1 2 3 |

2 | a c |
3 1 |
F | x x z |
1 1 1 |

## Export to CSV and SQL

NOT multilines

- Value sequences are serialized as a CSV string
- Value type is altered
- Not suitable for subset and query

ID | A | B | G | C | D |
---|---|---|---|---|---|

1 | a,b | 1,2 | M | x,y,z | 1,2,3 |

2 | a,c | 3,1 | F | x,x,z | 1,1,1 |

## Export to CSV and SQL

Multilines

- One row per occurrence
- Value type is correct
- Ready for subset and query

ID | A | B | G | C | D |
---|---|---|---|---|---|

1 | a | 1 | M | x | 1 |

1 | b | 2 | M | y | 2 |

1 | M | z | 3 | ||

2 | a | 3 | F | x | 1 |

2 | c | 1 | F | x | 1 |

2 | F | z | 1 |

## Future: Transposition

- One variable per occurrence
- Variable derivation wizard

ID | A1 | A2 | B1 | B2 |
---|---|---|---|---|

1 | a | b | 1 | 2 |

2 | a | c | 3 | 1 |