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K-dimensional mutually exciting process with kernel matrix \(\phi_{jk}(u) = a_{jk} \beta e^{-\beta u}\): MLE via the exact log-likelihood with the O(n) exponential recursion per (j,k) pair.

Usage

morie_crim_hawkes_multivariate(times, marks, t_max = NULL, beta = NULL)

Arguments

times

Numeric event times.

marks

Integer/factor component labels (length of times).

t_max

Observation horizon. Default max(times).

beta

Fixed decay rate (shared); estimated when NULL via an outer profile grid.

Value

List of class "morie_mv_hawkes": mu (K-vector), A (KxK excitation matrix), beta, loglik, spectral_radius, n, converged, call.

References

Hawkes (1971) Biometrika 58(1).

Examples

set.seed(2)
tt <- sort(runif(150, 0, 100)); mk <- sample(1:2, 150, TRUE)
morie_crim_hawkes_multivariate(tt, mk, beta = 1)
#> Multivariate Hawkes (K = 2, beta = 1), n = 150
#>   mu: 0.7281 0.6693 
#>   A:
#>        [,1] [,2]
#> [1,] 0.0000    0
#> [2,] 0.1697    0
#>   spectral radius = 0.001