 # Special-Purpose Software: BLUE Extreme Value Type I Estimation

Introduction - BLUE WIND BLUE WIND is a suite of Matlab programs that calculates the extreme wind speeds corresponding to specified Mean Return Intervals (MRI) for thunderstorms and non-thunderstorm events from the NIST database http://www.itl.nist.gov/div898/winds/datasets.htm or from a user-defined time series of annual wind speed peaks.

The suite consists of:

• The AnnualWindSpeed script which is used to extract the wind speed annual peak data for thunderstorms and non-thunderstorms from an Excel sheet populated with wind speed data from the NIST database.

• The blue8 script which performs the computations.

It fits the data to a Gumbel distribution based on Lieblein's best linear unbiased estimation (BLUE) as described in

Lieblein, J. (1974) “Efficient Methods of Extreme Value Methodology,” NBSIR 74-602, National Bureau of Standards, Washington, DC 20234.

In addition to the location and scale parameters of the fitted Gumbel distribution, the Matlab script blue8 returns extreme wind speeds corresponding to specified Mean Return Intervals.

• The function bluecoeff, which provides the coefficients of BLUE for 4 ≤ n epochs ≤ 100. The bluecoeff script is called by blue8.

These scripts were developed and tested using version 2014b of Matlab.

Introduction - BLUE PRESSURE BLUE PRESSURE is a suite of Matlab programs that calculates the extreme positive and negative (suction) wind pressure using Lieblein's BLUE method.

The suite consists of:

• The Matlab function blue4pressure, which estimates the extreme pressures and calls bluecoeff.

• The function bluecoeff, which provides the coefficients of BLUE for 4 ≤ n epochs ≤ 100.

These scripts were developed and tested using version 2014b of Matlab.

• blue_wind_manual.docx - User's Guide (Word format).
• blue8.m - this Matlab script estimates the extreme wind speeds and calls bluecoeff.
• bluecoeff.m - this Matlab script is called by blue8 to provide the coefficients of BLUE for 4 ≤ n epochs ≤ 100.
• AnnualWindSpeed.m - given the name of the Excel sheet from the NIST database, this Matlab script extracts the time series of annual peaks of thunderstorm and non-thunderstorm wind speeds.
The following files are tutorial examples.
• wind_speed.m - sample Matlab script to compute wind speed extremes using the Excel sheet Bakersfield_723840. It uses the AnnualWindSpeed.m Matlab script to perform the data extraction and blue8.m to perform the calculations.
• wind_speed2.m - sample Matlab script to compute wind speed extremes from the WASP.csv file. It uses blue8.m to perform the calculations. It assumes the WASP.csv file is in the C:\windPRESSURE directory.
• Bakersfield_723840.xlsx - sample Excel file used by the wind_speed.m script (Excel file).
• WASP.csv - sample ASCII file used by the wind_speed2.m script (ASCII file).