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Compute the rank (R) of a P-th percentile. This is done using the following formula:
R = P/100 x (N + 1)
where P is the desired percentile and N is the number of input fields.Compute the percentile:
If R is an integer, the P-th percentile will be the number with rank R.
If R is not an integer, the P-th percentile is computed by interpolation as follows:
If the interpolation method is Nearest Neighbour, the following equation is used:
P-th = V[int(R + 0.5)]If the interpolation method is Linear, the following steps are used:
Define IR as the integer portion of R
Define FR as the fractional portion or R
Find the scores with Rank IR and with Rank IR + 1, e.g. V[IR] and V[IR+1]
Interpolate by multiplying the difference between the scores by FR and add the result to the lower score, e.g.
Pth = FR * (V[IR+1] - V[IR]) + V[IR]
Compute if Missing
Specifies how to handle the presence of missing values in the input data.
- On (this is the default)
- for each grid point, the percentiles are computed using only the non-missing values
- Off
- for each grid point, if there are any missing values, the result for that point will be a missing value