function c = matmul9(a,b)
	% Function to multiply two 3x3 matricies stored as 9-col arrays (lay matrix out by rows)
	%  	I probably should have layed them in by columns - too late for this meeting!
	%		Created Oct 1, 2000 (Japan)
	%		a		=		first matrix as 9-col array (matrix stored by rows)
	%		b		=		second matrix
	%		c		=		product matrix (also 9-col)
	
	c(:,1)	= a(:,1).*b(:,1) + a(:,2).*b(:,4) + a(:,3).*b(:,7);
	c(:,2)	= a(:,1).*b(:,2) + a(:,2).*b(:,5) + a(:,3).*b(:,8);	
	c(:,3)	= a(:,1).*b(:,3) + a(:,2).*b(:,6) + a(:,3).*b(:,9);
	
	c(:,4)	= a(:,4).*b(:,1) + a(:,5).*b(:,4) + a(:,6).*b(:,7);
	c(:,5)	= a(:,4).*b(:,2) + a(:,5).*b(:,5) + a(:,6).*b(:,8);	
	c(:,6)	= a(:,4).*b(:,3) + a(:,5).*b(:,6) + a(:,6).*b(:,9);
	
	c(:,7)	= a(:,7).*b(:,1) + a(:,8).*b(:,4) + a(:,9).*b(:,7);
	c(:,8)	= a(:,7).*b(:,2) + a(:,8).*b(:,5) + a(:,9).*b(:,8);	
	c(:,9)	= a(:,7).*b(:,3) + a(:,8).*b(:,6) + a(:,9).*b(:,9);
	
	return)