Multiyear daily running percentile values
ydrunpctl.RdThis operator writes running percentile values for each day of year in infile1 to outfile. A certain percentile is computed for all timesteps in running windows of which the medium timestep corresponds to a certain day of year. The algorithm uses histograms with minimum and maximum bounds given in infile2 and infile3, respectively. The default number of histogram bins is 101. The default can be overridden by setting the environment variable CDO_PCTL_NBINS to a different value. The files infile2 and infile3 should be the result of corresponding ydrunmin and ydrunmax operations, respectively. The date information in an output field is the date of the timestep in the middle of the last contributing running window. Note that the operator have to be applied to a continuous time series of daily measurements in order to yield physically meaningful results. Also note that the output time series begins (nts-1)/2 timesteps after the first timestep of the input time series and ends (nts-1)/2 timesteps before the last. For input data which are complete but not continuous, such as time series of daily measurements for the same month or season within different years, the operator only yields physically meaningful results if the input time series does include the (nts-1)/2 days before and after each period of interest. o(001,x) = pth percentile {i(t,x), i(t+1,x), ..., i(t+nts-1,x); day[(i(t+(nts-1)/2)] = 001} ... o(366,x) = pth percentile {i(t,x), i(t+1,x), ..., i(t+nts-1,x); day[(i(t+(nts-1)/2)] = 366}