get_continuity.m

function cont_gamma = get_continuity(model,A,W)
%function cont_gamma = get_continuity(model,A,W)
%
% This function computes the coercivity constant alpha for a discrete
% operator K with respect to the inner product matrix (mass matrix) W.
%
% A generalized eigenvalue problem is solved for obtaining the continuity
% constant gamma.
%
% input:
%  - K: Operator Matrix
%  - W: inner product matrix
% 
% output:
%  - cont_gamma : continuity constant.
%
% This function does exactly the same as get_infsup.m
% but returns the largest eigenvalue.
%
% Oliver Zeeb

Y=A'*(W\A);
cont_gamma = sqrt(eigs(Y,W,1));