Exponential analysis

Performs a fast exponential analysis on the POT dataset stored in array X.

This M file performs a fast exponential analysis on the POT dataset stored in array X

INPUT:
X: array or scalar values with POT data (peaks over threshold)
tp: time period over which the data is collected
p: probability for which quantile has to be calculated

OUTPUT:
xp: quantile value corresponding to exceedance probability p
sp: uncertainty in quantile value expressed as 1 standard deviation
Figure, showing the POT data, exponential fit, and uncertainty bounds by crosses around the extrapolation to the p-value