From: spellucci@mathematik.tu-darmstadt.de (Peter Spellucci)
Subject: Re: gauss integration
Date: 7 Jan 2000 15:49:42 GMT
Newsgroups: sci.math.num-analysis
Summary: Nodes for Gaussian integration over a square

In article <3875B21F.E6D4A871@eng.uct.ac.za>,
 Kanshukan Rajaratnam <kanshu@eng.uct.ac.za> writes:
|> I am modelling flow using finite element method.
|> 
|> Can anyone tell me the integration points when integrating a
|> quadrilateral element at three points using the Gauss integration
|> method.
|> 
|> Thank you

from  stroud, approximate calculation of multiple integrals, page 229:
C_2 , the square -1<= x1 <=1 , -1<= x2 <= 1
degree 2 exact: 3 points:
coeff    (1/3)*Volume for all points
points    (r_{i,1} , r_{i,2} )  i=0,1,2,

           r_{i,1}= sqrt(2/3)*cos(2*i*pi/3) 
           r_{i,2}= sqrt(2/3)*sin(2*i*pi/3)        
hope that helps
peter