which is the lnorm of a vector x.
IZAMAX and ICAMAX return the smallest index i where
Note that this does not return an index i such that
which is the lnorm for a complex vector.
Note also that the FORTRAN interfaces return an index based at one while the C interfaces return an index based at zero. This is in keeping with the convention of each language in which the first element of a FORTRAN array is usually 1 and the first element of a C array is 0.

x: 
( 5.0,4.0) 
(3.0,2.0) 
( 5.0,4.0) 
( 6.0, 0.0) 
( 0.0, 8.0) 
Largest element in the vector x is item 1 