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triint

PURPOSE

integrate u over Omega given by p(oints) and t(riangles)

SYNOPSIS

function i=triint(u,p,t)

DESCRIPTION

 integrate u over Omega given by p(oints) and t(riangles)
 u=1 component of nodal values, i.e., size(u)=np x 1

CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

l1norm l1 norm of u, nodal and scalar, i.e., size(u)=np x 1
stanbra standard function for output to bifurcation diagram

SOURCE CODE

0001 function i=triint(u,p,t)  
0002 % integrate u over Omega given by p(oints) and t(riangles)
0003 % u=1 component of nodal values, i.e., size(u)=np x 1
0004 a1=t(1,:);a2=t(2,:);a3=t(3,:);% Corner point indices
0005 % Triangle sides
0006 r23x=p(1,a3)-p(1,a2);r23y=p(2,a3)-p(2,a2);r31x=p(1,a1)-p(1,a3);
0007 r31y=p(2,a1)-p(2,a3);
0008 ar=abs(r31x.*r23y-r31y.*r23x)/2;% areas of tiangles
0009 ut=pdeintrp(p,t,u);i=ut*ar';