# FOOTBALL Ranking Football Teams

FOOTBALL is a FORTRAN90 program which ranks college football teams.

A sample file of scores is available from Knuth's Stanford Graph Base. The program reads this file, computes a scoring matrix, and determines a ranking. At the moment, only some of Keener's methods have been implemented.

### Languages:

FOOTBALL is available in a FORTRAN90 version

### Related Data and Programs:

LADDERS, a C program which seeks to transform one five letter word into another, by changing one letter at a time, using only legitimate English words. This puzzle was invented by Lewis Carroll, who called it "Doublets", but it is also known as "Word Ladders" or "Word Gold". The program is by Donald Knuth.

SGB, a dataset directory which contains files used as input data for demonstrations and tests of Donald Knuth's Stanford Graph Base.

### Reference:

1. Donald Knuth,
The Stanford Graph Base,
ACM Press, 1993.
2. James Keener,
The Perron-Frobenius Theorem and the Ranking of Football Teams,
SIAM Review,
Volume 35, Number 1, pages 80-93, March 1993.

### List of Routines:

• MAIN is the main program for FOOTBALL.
• CH_CAP capitalizes a single character.
• CH_EXTRACT extracts the next nonblank character from a string.
• GAME_PRINT prints the game information.
• GET_UNIT returns a free FORTRAN unit number.
• I4_EXTRACT "extracts" an I4 from the beginning of a string.
• I4VEC_IDENTITY sets an I4VEC to the identity vector A(I)=I.
• PICARD uses Picard iteration to find an approximate nonlinear ranking.
• R8MAT_POWER_METHOD applies the power method to a matrix.
• R8VEC_SORT_INSERT_INDEX_D descending index sorts an R8VEC using insertion.
• S_BEFORE_SS_COPY copies a string up to a given substring.
• S_EQI is a case insensitive comparison of two strings for equality.
• S_TO_I4 reads an I4 from a string.
• S_TOKEN_MATCH matches the beginning of a string and a set of tokens.
• SCORE_MATRIX_SET sets the entries of the score matrix.
• SCORE_MATRIX_SET2 sets the entries of the score matrix.
• TEAM_PRINT prints the team name information.
• TEAM_READ reads the team name information from the game score data file.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• TOKEN_EXTRACT "extracts" a token from the beginning of a string.
• WARP computes a score that tries to factor out wipeouts.
• WARP2 computes a score that tries to factor out wipeouts.
• WORD_EXTRACT extracts the next word from a string.

You can go up one level to the FORTRAN90 source codes.

Last revised on 27 November 2006.