Superposed Epoch Analysis

Description

Superposed epoch analysis examines the significance of the input time series to user-specified key events (e.g., droughts, disease outbreaks). Departures from the mean during the event year and for a user-specified interval before and after the event year are computed. The mean pattern that emerges is then examined by bootstrap resampling to estimate the significance and determine if there might be predictability in the pattern of the input time series around the user-specified key events (see sea documentation in dplR library, Bunn 2008; R Core Development Team 2013 for further details).

Input Data

File
Select the input data to analyze by clicking on "Browse" and navigating to the proper file.

Input Data Format
Year / Data

Each "/" is a tab (i.e., data should be tab-delimited). Missing Data should be denoted as "-99".

Start Row
This input is the row number where the main data to be processed begin in the input file selected above. An example of how row numbers are entered is shown in Figure 2 located in the Running Dendro Tools topic.

Event Years
Enter the event years one line at a time (i.e., enter the first year, hit return, enter the second year, hit return, enter the third year, and so on).

Output Data

File
Select or enter the name of the file where the results will be stored.

Header
Information entered here will be output in the first line of the output file.

Parameters

Start Year
Enter the year to start the analysis.

End Year
Enter the year to end the analysis.

Years +/- Event to Analyze
Enter the number of years before and after the events to analyze for significant departures from the mean (default = 5).

Number of Resamples
Enter the number of bootstrap resamples that will be used to the estimate the significance (default = 1000).