matrix.out
>> a = [3 2 -1; -1 3 2; 1 -1 -1] % 'a' 3X3 coeff matrix
a =
3 2 -1
-1 3 2
1 -1 -1
>> b = [ 10; 5; -1] % 'b' RHS (load) vector
b =
10
5
-1
>> x = a\b % from a * x = b, solve for x
x =
-2.0000
5.0000
-6.0000
>> a*x % check that a * x = b
ans =
10.0000
5.0000
-1.0000
>> inva = inv(a) % determine inverse of 'a'
inva =
-1.0000 3.0000 7.0000
1.0000 -2.0000 -5.0000
-2.0000 5.0000 11.0000
>> inva * a % check that inva * a = [I]
ans =
1.0000 0.0000 0.0000
0.0000 1.0000 0.0000
0.0000 0.0000 1.0000
>> inva * b % show that inva * b = x
ans =
-2.0000
5.0000
-6.0000
>> a' % transpose of 'a'
ans =
3 -1 1
2 3 -1
-1 2 -1
>> cond(a) % condition number of 'a'
ans =
63.0547