pyPDAF.PDAF.diag_histogram

pyPDAF.PDAF.diag_histogram()

Computing the rank histogram of an ensemble.

A rank histogram is used to diagnose the reliability of the ensemble [1]. A perfectly reliable ensemble should have a uniform rank histogram.

The function can be called in the pre/poststep routine of PDAF both before and after the analysis step to collect the histogram information.

References

Parameters:

  • ncall (int) – Number of calls to routine

  • dim (int) – State dimension

  • dim_ens (int) – Ensemble size

  • element (int) – Element of vector used for histogram

  • state (ndarray[np.float64, ndim=1]) – State vector Array shape: (dim)

  • ens (ndarray[np.float64, ndim=2]) – State ensemble Array shape: (dim, dim_ens)

  • hist (ndarray[np.intc, ndim=1]) – Histogram about the state Array shape: (dim_ens+1)

Returns:

  • hist (ndarray[np.intc, ndim=1]) – Histogram about the state Array shape: (dim_ens+1)

  • delta (double) – deviation measure from flat histogram

  • status (int) – Status flag (0=success)