Presence/Absence coding
Presence-absence coding helps you transform lists of attributes (or species) to a dataset that can be analyzed using statistical procedures.
Why do we use presence/absence coding
In many domains, data are available as sets of lists of attributes (a list by statistical individual). It might be a list of pharmaceutical properties for a list of plants, or a list of occurrences of species in a biotope. These lists cannot be manipulated by most statistical tools, and therefore, they first need to be transformed into a presence/absence table, where each cell has a 0 if the attribute is absent and a 1 if the attribute is present.
Presence/Absence coding in XLSTAT
Converting a table of attributes into a table of presences/absences showing the frequencies of the various elements for each of the lists has never been easier. You simply need to select the table in the XLSTAT tool for Presence/Abcense coding and the new table will be generated instantly.
Below you can find an example of presence/absence coding. Based on a table of two lists containing various elements, a presence/absence coding summarizes the presence of the elements in each list.
| List 1 | List 2 |
| E1 E1 E2 E1 E3 | E3 E1 E4 |
Table with presence and absence coding:
| E1 | E2 | E3 | E4 | |
| List 1 | 1 | 1 | 1 | 0 |
| List 2 | 1 | 0 | 1 | 1 |