NORM

The NORM function computes the Euclidean norm of a vector. Alternatively, NORM computes the Infinity norm of an array.

This routine is written in the IDL language. Its source code can be found in the file norm.pro in the lib subdirectory of the IDL distribution.

Result = NORM( A )

A can be either of the following:

An n -element real or complex vector, if NORM is being used to compute the Euclidean norm of a vector.
An m by n real or complex array, if NORM is being used to compute the Infinity norm of an array.

Set this keyword to force the computation to be done in double-precision arithmetic.

Define an n -element complex vector A:

A = [COMPLEX(1, 0), COMPLEX(2,-2), COMPLEX(-3,1)]

PRINT, NORM(A) ; Compute the Euclidean norm of A and print.

IDL prints:

4.35890

Define an m by n complex array A:

B = [[COMPLEX(1, 0), COMPLEX(2,-2), COMPLEX(-3,1)], $

[COMPLEX(1,-2), COMPLEX(2, 2), COMPLEX(1, 0)]]

PRINT, NORM(B, /DOUBLE) ; Compute the Infinity norm of B and print.

IDL prints:

6.9907048