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Re: Double formatting bug? [message #6601 is a reply to message #6593]

Mon, 20 November 2006 10:12

rylek
Messages: 79
Registered: November 2005

Member

Hello!

I think that is not a bug. FD_FIX, just as FD_EXP, are bit-coded option flags for the FormatDouble function affecting the choice of number output format. When you use, e.g.,

FormatDouble(32.5, 3, FD_FIX)

it always gets formatted in the "traditional" way (as 32.5). On the other hand, calling

FormatDouble(32.5, 3, FD_EXP)

causes the number to be always formatted in the scientific exponential notation (3.25e1). If neither of the option flags are used, FormatDouble selects the appropriate format automatically based on magnitude of the number being formatted (the code within the if-block).

I believe that these three variants (traditional output notation, exponential output notation, autoselect based on magnitude) correspond to the NFormat specifiers %nf, %ne, and %n, respectively. However the formatting function (RealFormatter) directly calls the appropriate formatting functions as necessary (FormatDoubleExp / FormatDoubleFix) so that the call to FormatDouble is used only exactly to invoke the magnitude-based format autoselection mechanism, so neither FD_FIX nor FD_EXP is used there.

Regards

Tomas

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