#guass-jordan for matrix inversion

A=matrix(QQ, [[-1,1,2],[3,-1,1],[-1,3,4]])
I=matrix(QQ, [[1,0,0],[0,1,0],[0,0,1]])

A.add_multiple_of_row(1, 0, 3)
A.add_multiple_of_row(2, 0, -1)
A.add_multiple_of_row(2, 1, -1)
A.add_multiple_of_row(1, 2,7/5 )
A.add_multiple_of_row(0, 2, 2/5)
A.add_multiple_of_row(0, 1, -1/2)
A.rescale_row(0, -1)
A.rescale_row(1, 1/2) 
A.rescale_row(2, -1/5)  
print A

I.add_multiple_of_row(1, 0, 3)
I.add_multiple_of_row(2, 0, -1)
I.add_multiple_of_row(2, 1, -1)
I.add_multiple_of_row(1, 2,7/5 )
I.add_multiple_of_row(0, 2, 2/5)
I.add_multiple_of_row(0, 1, -1/2)
I.rescale_row(0, -1)
I.rescale_row(1, 1/2) 
I.rescale_row(2, -1/5)  

print I
#here I is inverse of A

Kreyszig-Kreyszig 6.7-1 (last edited 2010-12-17 12:22:19 by beesanna)