test_inverse.f90 on tough to invert matrix
 initializing big matrix, n= 2 , n*n= 4
 data
 AA( 1 , 1 )= 0.500000000000000
 AA( 1 , 2 )= 0.333333333333333
 AA( 2 , 1 )= 0.333333333333333
 AA( 2 , 2 )= 0.250000000000000
 inverse
 AI( 1 , 1 )= 18.0000000000000
 AI( 1 , 2 )= -24.0000000000000
 AI( 2 , 1 )= -24.0000000000000
 AI( 2 , 2 )= 36.0000000000000
 sum of error= 1.84748050191530E-16 , avg error= 4.61870125478825E-17
 initializing big matrix, n= 4 , n*n= 16
 data
 AA( 1 , 1 )= 0.500000000000000
 AA( 1 , 2 )= 0.333333333333333
 AA( 1 , 3 )= 0.250000000000000
 AA( 1 , 4 )= 0.200000000000000
 AA( 2 , 1 )= 0.333333333333333
 AA( 2 , 2 )= 0.250000000000000
 AA( 2 , 3 )= 0.200000000000000
 AA( 2 , 4 )= 0.166666666666667
 AA( 3 , 1 )= 0.250000000000000
 AA( 3 , 2 )= 0.200000000000000
 AA( 3 , 3 )= 0.166666666666667
 AA( 3 , 4 )= 0.142857142857143
 AA( 4 , 1 )= 0.200000000000000
 AA( 4 , 2 )= 0.166666666666667
 AA( 4 , 3 )= 0.142857142857143
 AA( 4 , 4 )= 0.125000000000000
 inverse
 AI( 1 , 1 )= 200.000000000069
 AI( 1 , 2 )= -1200.00000000049
 AI( 1 , 3 )= 2100.00000000093
 AI( 1 , 4 )= -1120.00000000052
 AI( 2 , 1 )= -1200.00000000048
 AI( 2 , 2 )= 8100.00000000338
 AI( 2 , 3 )= -15120.0000000064
 AI( 2 , 4 )= 8400.00000000362
 AI( 3 , 1 )= 2100.00000000092
 AI( 3 , 2 )= -15120.0000000064
 AI( 3 , 3 )= 29400.0000000122
 AI( 3 , 4 )= -16800.0000000069
 AI( 4 , 1 )= -1120.00000000052
 AI( 4 , 2 )= 8400.00000000361
 AI( 4 , 3 )= -16800.0000000069
 AI( 4 , 4 )= 9800.00000000385
 sum of error= 2.19971263426544E-12 , avg error= 1.37482039641590E-13
 initializing big matrix, n= 8 , n*n= 64
 sum of error= 0.00000604139304982709 , avg error= 9.43967664035483E-8
 initializing big matrix, n= 16 , n*n= 256
 sum of error= 83.9630735209012 , avg error= 0.327980755941020
 initializing big matrix, n= 32 , n*n= 1024
 sum of error= 4079.56590417946 , avg error= 3.98395107830025
 initializing big matrix, n= 64 , n*n= 4096
 sum of error= 53735.8765782488 , avg error= 13.1191104927365
 initializing big matrix, n= 128 , n*n= 16384
 sum of error= 85784.2643647822 , avg error= 5.23585597929579
 initializing big matrix, n= 256 , n*n= 65536
 sum of error= 1097119.16168229 , avg error= 16.7407098645368
 initializing big matrix, n= 512 , n*n= 262144
 sum of error= 1.36281435213093E+7 , avg error= 51.9872418262837
 initializing big matrix, n= 1024 , n*n= 1048576
 sum of error= 1.24247404738082E+9 , avg error= 1184.91558778841
 finished test_inverse.f90