Identity line: Difference between revisions

In a 2-dimensional [[Cartesian coordinate system]], with ''x'' representing the [[abscissa]] and ''y'' the [[ordinate]], the '''identity line''' is the ''y'' = ''x'' line. The line, sometimes called the '''1:1 line''', has a [[slope]] of 1. When the abscissa and ordinate are on the same scale, the identity line forms a 45° angle with the abscissa, and is thus also, informally, called the '''45° line'''. The line is often used as a reference in a 2-dimensional [[scatter plot]] comparing two sets of data expected to be identical under ideal conditions. When the corresponding data points from the two data sets are equal to each other, the corresponding scatters fall exactly on the identity line.

 

{{Unreferenced|date=September 2010}}