# Units

Specify the units for distance, time and rotation:. Changing the units does not affect the raw data, only their presentation. You can change the displayed units at any time.

Unit of distance

EthoVision measures the distance between two points in pixels. To convert these to real values you must calibrate your arena. Here, you can choose what unit of distance you prefer: millimeters (mm), centimeters (cm), meters (m) or inches (inch).

Unit of time:

Milliseconds (ms), seconds (s), minutes (min) or hours (hr).

Unit of rotation:

Degrees (°), radians (rad), gradians (grad) or rotations (rot).

Notes

▪You can change the units after you have acquired tracks. This only affects the presentation; the data are always correct.

▪Changing the units only affects the present experiment. To change the default units for future experiments, choose File > Preferences. Click Default units and select the units you want.

▪Settings of units are saved on your computer. If you open another EthoVision XT experiment from a colleague, numbers will be displayed according to your settings, regardless of the settings your colleague used. For example, your colleague tracked an animal moving one inch; on your computer it is shown as 2.54 cm.