* Sign of tanh ??? @ 2001-04-21 11:35 Bobby D. Bryant 2001-04-22 14:56 ` Wilhelm Spickermann 0 siblings, 1 reply; 3+ messages in thread From: Bobby D. Bryant @ 2001-04-21 11:35 UTC (permalink / raw) Isn't tanh supposed to preserve the sign of its argument? ---8<------- with Ada.Float_Text_IO, Ada.Numerics.Elementary_Functions; use Ada.Float_Text_IO, Ada.Numerics.Elementary_Functions; procedure Test is begin Put( Tanh( 0.5 ), Fore => 3, Exp => 0 ); Put( Tanh( -0.5 ), Fore => 3, Exp => 0 ); end Test; ---8<------- % gnatmake test gnatgcc -c test.adb gnatbind -x test.ali gnatlink test.ali gnatlink: warning: executable name "test" may conflict with existing command % ./test 0.46212 0.46212 % rpm -q gnat gnat-3.13p-5 Thanks, Bobby Bryant Austin, Texas ^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: Sign of tanh ??? 2001-04-21 11:35 Sign of tanh ??? Bobby D. Bryant @ 2001-04-22 14:56 ` Wilhelm Spickermann 2001-04-22 7:12 ` Bobby D. Bryant 0 siblings, 1 reply; 3+ messages in thread From: Wilhelm Spickermann @ 2001-04-22 14:56 UTC (permalink / raw) To: comp.lang.ada [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #1: Type: text/plain; charset=us-ascii, Size: 383 bytes --] On 21-Apr-01 Bobby D. Bryant wrote: > Isn't tanh supposed to preserve the sign of its argument? Sure. But I get the result 0.46212 -0.46212 and I use the gnat-3.13p-5 rpm (from ALT) too. Perhaps it�s the C-library. Gnat uses the C-Library to compute the tanh (if the result cannot be easily found to be -1.0 1.0 or the argument). Does the problem occur in C too? Wilhelm ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Sign of tanh ??? 2001-04-22 14:56 ` Wilhelm Spickermann @ 2001-04-22 7:12 ` Bobby D. Bryant 0 siblings, 0 replies; 3+ messages in thread From: Bobby D. Bryant @ 2001-04-22 7:12 UTC (permalink / raw) Wilhelm Spickermann wrote: > On 21-Apr-01 Bobby D. Bryant wrote: > > Isn't tanh supposed to preserve the sign of its argument? > > Sure. But I get the result > 0.46212 -0.46212 > and I use the gnat-3.13p-5 rpm (from ALT) too. > > Perhaps it´s the C-library. Gnat uses the C-Library to compute the tanh (if > the result cannot be easily found to be -1.0 1.0 or the argument). Does the > problem occur in C too? No, it works OK in C. Odd... Bobby Bryant Austin, Texas ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2001-04-22 14:56 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2001-04-21 11:35 Sign of tanh ??? Bobby D. Bryant 2001-04-22 14:56 ` Wilhelm Spickermann 2001-04-22 7:12 ` Bobby D. Bryant
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