Abstract
Cross recurrence plots are visualizations that show recurrences of simultaneous occurrences of states of two dynamical systems, while joint recurrence plots graphically exhibit simultaneous occurrences of recurrences of two or more dynamical systems. In this paper, fuzzy cross and fuzzy joint recurrence plots are introduced using minimum T-norm and product T-norm to reveal cross and joint recurrences of states of dynamical systems, respectively. Not only fuzzy cross and fuzzy joint recurrence plots are able to relax the constraint of the similarity threshold imposed on cross and joint recurrence plots, but also provide a measure of evidence of the recurrence.
•Joint recurrence plots show simultaneous occurrences of two dynamical systems.•Cross recurrence plots exhibit simultaneous occurrences of two or more dynamical systems.•Fuzzy joint recurrence and fuzzy cross recurrence plots are introduced in this paper.•The fuzzy recurrence algorithms are more informative than the non-fuzzy recurrence versions.