# Extract the phi-coefficient observed between the two time-series on a specific state k.

### Description

Phi-coefficient is the recurrence observed between the two time-series on a specific state k. The phi(k) coefficient increases with the frequency of matching recurrence on the same state (k ; k) and away from this state (not k ; not k) between the two time-series. On the other hand, phi(k) decreases with the frequency of mismatching objects (k; not-k, and vice versa).

### Usage

1 | ```
calcphi(t1, t2, ws, k)
``` |

### Arguments

`t1` |
First time-series |

`t2` |
Second time-series |

`ws` |
Number of delays (+/-) considered |

`k` |
The categorical state on which phi is calculated |

### Value

It returns the recurrence phi-coefficient profile for state k for all delays considered

### Author(s)

Moreno I. Coco (moreno.cocoi@gmail.com)

### References

Dale, R., Warlaumont, A. S. and Richardson, D. C. (2011). Nominal cross recurrence as a generalized lag sequential analysis for behavioral streams. International Journal of Bifurcation and Chaos, 21, 1153-1161. (special issue on recurrence)

### See Also

`CTcrqa`

, `simts`

### Examples

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