The TRACE function computes the trace of an n by n array.
This routine is written in the IDL language. Its source code can be found in the file trace.pro in the lib subdirectory of the IDL distribution.
trace.pro
lib
Result = TRACE( A )
An n by n real or complex array.
Set this keyword to force the computation to be done in double-precision arithmetic.
Define an array.
A = [[ 2.0,1.0, 1.0, 1.5], $
[ 4.0, -6.0, 0.0, 0.0], $
[-2.0, 7.0, 2.0, 2.5], $
[ 1.0, 0.5, 0.0, 5.0]]
result = TRACE(A) ; Compute the trace of A.
PRINT, result ; Print Result.
IDL prints:
3.00000
TOTAL
