initial matrix A 
MAT[0,0] = 3.000000 
MAT[0,1] = 2.000000 
MAT[0,2] = 100000.000000 
MAT[1,0] = -1.000000 
MAT[1,1] = 3.000000 
MAT[1,2] = 100000.000000 
MAT[2,0] = 1.000000 
MAT[2,1] = 2.000000 
MAT[2,2] = -1.000000 
initial vector Y 
VEC[0] = 100005.000000 
VEC[1] = 100002.000000 
VEC[2] = 2.000000 
solve equations 
solution X 
VEC[0] = 1.000000 
VEC[1] = 1.000000 
VEC[2] = 1.000000 
initializing big matrix, n=2, n*n=4 
initialization complete, solving 
MAT[0,0] = 0.500000 
MAT[0,1] = 0.333333 
MAT[1,0] = 0.333333 
MAT[1,1] = 0.250000 
VEC[0] = 0.250000 
VEC[1] = 0.250000 
solution XX[0]=-1.5, err=-5.55112e-17 
       XX[n-1]=3, err=0 

initializing big matrix, n=4, n*n=16 
initialization complete, solving 
MAT[0,0] = 0.500000 
MAT[0,1] = 0.333333 
MAT[0,2] = 0.250000 
MAT[0,3] = 0.200000 
MAT[1,0] = 0.333333 
MAT[1,1] = 0.250000 
MAT[1,2] = 0.200000 
MAT[1,3] = 0.166667 
MAT[2,0] = 0.250000 
MAT[2,1] = 0.200000 
MAT[2,2] = 0.166667 
MAT[2,3] = 0.142857 
MAT[3,0] = 0.200000 
MAT[3,1] = 0.166667 
MAT[3,2] = 0.142857 
MAT[3,3] = 0.125000 
VEC[0] = 0.062500 
VEC[1] = 0.062500 
VEC[2] = 0.062500 
VEC[3] = 0.062500 
solution XX[0]=-1.25, err=-4.27392e-16 
       XX[n-1]=17.5, err=-4.44089e-16 

initializing big matrix, n=8, n*n=64 
initialization complete, solving 
solution XX[0]=-1.125, err=-1.19732e-12 
       XX[n-1]=1608.75, err=-3.97904e-13 

initializing big matrix, n=16, n*n=256 
initialization complete, solving 
solution XX[0]=0.668676, err=3.08463e-08 
       XX[n-1]=354947, err=1.11741e-08 

initializing big matrix, n=32, n*n=1024 
initialization complete, solving 
solution XX[0]=-0.0958061, err=4.48695e-05 
       XX[n-1]=499476, err=1.23342e-05 

initializing big matrix, n=64, n*n=4096 
initialization complete, solving 
solution XX[0]=-0.0885967, err=0.00289389 
       XX[n-1]=-280410, err=0.000433751 

initializing big matrix, n=128, n*n=16384 
initialization complete, solving 
solution XX[0]=0.00270503, err=0.0275091 
       XX[n-1]=125862, err=0.00289606 

initializing big matrix, n=256, n*n=65536 
initialization complete, solving 
solution XX[0]=0.0116177, err=2.22468 
       XX[n-1]=69581.1, err=0.112949 

initializing big matrix, n=512, n*n=262144 
initialization complete, solving 
solution XX[0]=0.0132836, err=-20.7464 
       XX[n-1]=-201559, err=-0.502377 

initializing big matrix, n=1024, n*n=1048576 
initialization complete, solving 
solution XX[0]=-0.000541711, err=-21.0739 
       XX[n-1]=-1933.02, err=-0.280531