This directory contains functions that compute the Erlang B (blocked
calls lost) and Erlang C (blocked calls wait) probabilities.  The
usual textbook formula is unsuitable for direct evaluation because of
round-off error.  These functions make use of a recurrence relation
which is more accurate, particularly for situations where the number
of servers and the load are both large.

The latest version of this code adds a routine for computing the
Engset blocking probability E, for a system with n servers, m
customers, and intensity rho.

The functions are:
 
  erlangb                   Find B, given n and rho.
  erlangc                   Find C, given n and rho.
  erlangbinv                Find n such that B<=p, rho fixed.
  erlangcinv                Find n such that C<=p, rho fixed.
  findrhob                  Find rho such that erlangb(n,rho)=p, given n, p.
  findrhoc                  Find rho such that erlangc(n,rho)=p, given n, p.
  engset                    Find E, given m, n, and rho.

Brian Borchers                          borchers@nmt.edu              
Department of Mathematics               http://euler.nmt.edu/~brian/   
New Mexico Tech                         Phone: 505-835-5813              
Socorro, NM 87801                       FAX: 505-835-5366"




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