Modern Math CToString

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CToString

Returns a complex number as text such as 3+4i that reads back exactly.

Syntax

CToString( byref z as Complex ) as string

Notes

• Built on ToString from mathtext.tiko, so the components round-trip: what TryParseDouble gives back is bit-for-bit what went in. STR does not promise that and does not deliver it.
• The sign is emitted separately from the magnitude so that a negative zero survives. "3-0i" parses back to -0.0, where "3+0i" would not — and which zero an operand carries is what decides the side of a branch cut.
• The non-finite components come out as "nan", "inf" and "-inf", all of which TryParseDouble accepts again. A NaN is not equal to itself, though, so what survives that trip is the spelling and not the value.
• CStr is a keyword, which is why AfxNova's CStr( z ) could not keep its name.

Examples

#import "std/numeric"
using numeric

print CToString( CSet( 3, 4 ) )          '' 3+4i
print CToString( CSet( 3, -4 ) )         '' 3-4i
print CToString( CSet( 3, -0.0 ) )       '' 3-0i   -- the negative zero survives
print CToString( CSet( 0.1 + 0.2, 0 ) )  '' 0.30000000000000004+0i   -- shortest round-trip, not STR
print str( 0.1 + 0.2 )                   '' 0.3   -- STR, for comparison

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