还有还有估计gumbel copula
> gumbel.cop <- gumbelCopula(dim=2)
> fit <- fitCopula(gumbel.cop,m,method="ml")
Warning message:
In .local(copula, tau, ...) :
For the Gumbel copula, tau must be >= 0. Replacing negative values by 0.
> coef(fit)
中间也报错了,但是也有估计结果,这又是什么意思呢?怎么解决才好啊