ROWNORM(<matrix>)
Finds the row norm of a matrix: the maximum, over all rows contained
in the matrix, of the absolute values of the sum of the elements in each
row.
⎡
1
2
3
⎤
⎢
=
Eg. For the matrix
M
1
4
5
6
⎥
⎥
, the row with the largest absolute sum of 15 is row 2.
⎢
⎢
−
1
5
4
⎥⎦
⎣
RREF(<matrix>)
This function takes an augmented matrix of size n by n+1 and transforms it into reduced row echelon form,
with the final column containing the solution.
−
2
3
14
⎫
x
y
z
=
+
⎪
Eg.
The system of equations
2
x
y
z
+ − = −
3
⎬
4
2
2
14
⎭
x
y
z
=
−
+
⎪
⎡
1
2
3
−
14
⎤
is written as the augmented matrix
⎢
⎢
2
1
1
−
−
3
⎥
⎥
⎢
4
2
2
⎣
−
14
⎥⎦
which is then stored as a 3x4 real matrix
M1
.
We now use the function
RREF
to change this to reduced row echelon
form and store it as
M2
.
This gives the final result shown in the matrix
M2
on the right, giving a
solution of (1, -2, 3).
The huge advantage of this function is that it allows for inconsistent
matrices which can’t be solved by an inverse matrix.
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