#   
# Written by:
# -- 
# John L. Weatherwax                2006-08-28
# 
# email: wax@alum.mit.edu
# 
# Please send comments and especially bug reports to the
# above email address.
# 
#-----

x = c(0,1,-2,3,-1,0,3,-4,2,-3,0,5,-3,4,-5,0)
M = matrix(x,nrow=4,ncol=4,byrow=FALSE)
M
det(M)

25 + 3* ( 15 ) + 4*(-10) + 2* (-20) + 8*(8-9) + 3*(15) - 9*(8-9) 

x = c(1,3,-4,-2,-6,14,3,3,-12)
M = matrix(x,nrow=3,ncol=3,byrow=FALSE)
M