Circumplex Model of Emotion

The circumplex model [of emotion] focuses on determining how traits and emotions are structurally similar, and its underlying assumption is that a relatively seamless circular ordering, or circumplex, is an economical description of the relations among traits and emotions.

Reference:

Russell, J. A. (1980). A circumplex model of affect. Journal of Personality and Social Psychology, 39(6), 1161. https://psycnet.apa.org/doi/10.1037/h0077714