Re: [Sbcl-devel] [Sbcl-commits] CVS: sbcl/src/code irrat.lisp, 1.32, 1.33

[Pierre R. M. <pm...@pm...>]

Am 30.10.2006 um 11:53 schrieb Nikodemus Siivola:

> Update of /cvsroot/sbcl/sbcl/src/code
> In directory sc8-pr-cvs8.sourceforge.net:/tmp/cvs-serv18144/src/code
>
> Modified Files:
> 	irrat.lisp
> Log Message:
> 0.9.18.17: Hyperbolic functions for Win32
>  * Lisp-side definitions for %TANH, %ASINH, %ACOSH, and %ATANH.

I think the %atanh definition contains a minor think-o, which breaks =20
atanh:

(atanh 0.9d0) on non-Win32:
1.4722194895832204d0

(atanh 0.9d0) on Win32:
#C(1.4722194895832204d0 1.5707963267948966d0)

> +  (declaim (inline %atanh))
> +  (defun %atanh (number)
> +    (let ((ratio (/ (1+ number) (1- number))))

I think you meant (/ (+ 1 number) (- 1 number)) here, with (- 1 =20
number) !=3D (1- number)...

Patch below that fixes this, SBCL rebuilds fine with this change, and =20=

delivers correct atanh results again.

Regs, Pierre.

Index: src/code/irrat.lisp
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- src/code/irrat.lisp (revision 4)
+++ src/code/irrat.lisp (working copy)
@@ -95,7 +95,7 @@
      (log (+ number (sqrt (- (* number number) 1.0d0))) #.(exp 1.0d0)))
    (declaim (inline %atanh))
    (defun %atanh (number)
-    (let ((ratio (/ (1+ number) (1- number))))
+    (let ((ratio (/ (+ 1 number) (- 1 number))))
        ;; Were we effectively zero?
        (if (=3D ratio -1.0d0)
            0.0d0

--=20
Pierre R. Mai                                        <pm...@pm...>
PMSF IT Consulting Pierre R. Mai                http://www.pmsf.de/
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