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On Saturday 22 October 2005 5:05 pm, Marco Matthies wrote: |
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> Darren Dale wrote: |
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> > On my system, SciPy's signbit function reports that the sign bit is not |
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> > set for any number, positive or negative. Could someone here help me |
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> > understand how to test the libc signbit function? I have to admit I have |
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> > no experience with C programming. |
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> |
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> Hi Darren, |
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> |
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> the signbit fuction is actually a macro (as the manpage says) defined in |
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> math.h that in turn calls the right inline function (for the type |
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> needed) which is defined in mathinline.h --- so as far as i can see, |
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> libc should not be involved, only header files. I have attached a small |
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> example below on how to use the function. Please note the use of |
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> -std=c99 (you may also use -std=gnu99) as the macro is only activated |
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> when in C99 mode and gcc's default mode is C89 ("ANSI C"). If you're |
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> interested in the differences between the two standards the wikipedia |
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> entry on c has some info: |
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> http://en.wikipedia.org/wiki/C_programming_language |
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|
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Hi Marko, |
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|
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Thank you for your thoughtful and informative response. I have learned a few |
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things. |
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|
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Your test shows that signbit is working just fine on my system. I will discuss |
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my results with the SciPy folks. |
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|
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Thanks again, |
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Darren |
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-- |
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