Primary Column

A dataset can contain multiple data columns of a particular type. For each type, one data column serves as the primary column, meaning the representative column for that type.

When comparing data of a certain type across multiple datasets, as in the graph below, Windographer displays only the primary column from each dataset:

You specify the primary column of each type in the Configure Dataset window on the Primary Columns tab. You can identify a specific data column by name, or you can choose a simple criterion such as the highest or lowest visible column, or the visible column nearest to some target height:

Any criterion that refers to measurement height makes use of the nearest-in-height rule.

Windographer also refers to primary columns in other situations, including when choosing which temperature and pressure sensors to use to calculate air density, and when choosing which speed and direction sensors to reconstruct first.