Modern Math CSgn

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CSgn

Returns a complex number scaled to modulus 1, or zero for zero.

Syntax

CSgn( byref z as Complex ) as Complex

Notes

• z / CAbs( z ), and CZero( ) for zero. This is Mathematica's Sign[z] and the only meaning of sign that survives on ℂ.
• Deliberately different from AfxNova, whose CSgn returned a LONG: +1 if the real part was positive, else -1 if negative, else the same test on the imaginary part. That is a lexicographic tie-break, not a sign, and this header declines to give ℂ an ordering. Code ported from AfxNova gets a compile error at the assignment rather than a silently different number.
• The result has modulus 1 and the same argument as the operand.

Examples

#import "std/numeric"
using numeric

dim as Complex z = CSet( 3, 4 )

print CToString( CSgn( z ) )         '' 0.6+0.8i
print CAbs( CSgn( z ) )              '' 1   -- always 1
print CToString( CSgn( CZero( ) ) )  '' 0+0i

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Library: Math Library
Category: Math Library
Documented under: Members