# climpred.metrics._spearman_r_eff_p_value¶

climpred.metrics._spearman_r_eff_p_value(forecast, verif, dim=None, **metric_kwargs)[source]

Probability that forecast and verification data are monotonically uncorrelated, accounting for autocorrelation.

Note

Weights are not included here due to the dependence on temporal autocorrelation.

Note

This metric can only be used for hindcast-type simulations.

The effective p value is computed by replacing the sample size in the t-statistic with the effective sample size, . The same Spearman’s rank correlation coefficient is used as when computing the standard p value.

where is computed via the autocorrelation in the forecast and verification data.

where and are the lag-1 autocorrelation coefficients for the forecast and verification data.

Parameters
Details:
 minimum 0.0 maximum 1.0 perfect 1.0 orientation negative
Reference:
• Bretherton, Christopher S., et al. “The effective number of spatial degrees of freedom of a time-varying field.” Journal of climate 12.7 (1999): 1990-2009.

Example

>>> HindcastEnsemble.verify(metric='spearman_r_eff_p_value', comparison='e2o',
...     alignment='same_verifs', dim='init')
<xarray.Dataset>