GNU bug report logs - #69725
Incorrect comapration between exact and inexact numbers

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Package: guile;

Reported by: Maciej <m.kalandyk <at> outlook.com>

Date: Mon, 11 Mar 2024 07:53:02 UTC

Severity: normal

Done: lloda <lloda <at> sarc.name>

Bug is archived. No further changes may be made.

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Report forwarded to bug-guile <at> gnu.org:
bug#69725; Package guile. (Mon, 11 Mar 2024 07:53:02 GMT) Full text and rfc822 format available.
Acknowledgement sent to Maciej <m.kalandyk <at> outlook.com>:
New bug report received and forwarded. Copy sent to bug-guile <at> gnu.org. (Mon, 11 Mar 2024 07:53:02 GMT) Full text and rfc822 format available.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Maciej <m.kalandyk <at> outlook.com>
To: bug-guile <at> gnu.org
Subject: Incorrect comapration between exact and inexact numbers
Date: Mon, 11 Mar 2024 08:46:16 +0100

description:

script(named main.scm):
(use-modules (srfi srfi-11))

(define* (newton-sqrt x #:optional (tolerance 0.001) (guess 1))
  (if (< (abs (- x (* guess guess)))
	 tolerance)
      (values guess (abs (- x (* guess guess))) tolerance)
      (newton-sqrt x tolerance (/ (+ guess (/ x guess)) 2))))

(let-values ([(root diff tolerance)
	      (newton-sqrt 1000)])
  (display (exact->inexact diff)) ;; 1.217168231948292
  (newline)
  (display tolerance) ;; 0.001
  (newline)
  ;; bug here 1.217 in exact form apparently is smaller than 0.001
  (display (< diff tolerance)) ;; #t
  (newline)
  (display (< diff (inexact->exact tolerance))) ;; #f
  (newline)
  (display (< (exact->inexact diff) tolerance)) ;; #f
  (newline))

guile version:
guile --version
guile (GNU Guile) 3.0.9

machine-type:
./config.guess
x86_64-pc-linux-gnu

system package:
guix package -V guile
guix package (GNU Guix) f18d13b5f89c161c6ee88d15ecdaa8d973ee4503

additional system info:
guix channels.scm
(list (channel
        (name 'guix)
        (url "https://git.savannah.gnu.org/git/guix.git")
        (branch "master")
        (commit
          "aeb494322ca9dec4a4d66a7d063239c8536bd538")
        (introduction
          (make-channel-introduction
            "9edb3f66fd807b096b48283debdcddccfea34bad"
            (openpgp-fingerprint
              "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA")))))

what i ran to run the script:
guix time-machine -C channels.scm -- shell --pure guile -- ./main.scm
1.217168231948292
0.001
#t
#f
#f
Information forwarded to bug-guile <at> gnu.org:
bug#69725; Package guile. (Mon, 18 Mar 2024 16:18:02 GMT) Full text and rfc822 format available.

Message #8 received at 69725 <at> debbugs.gnu.org (full text, mbox):

From: lloda <lloda <at> sarc.name>
To: Maciej <m.kalandyk <at> outlook.com>
Cc: 69725 <at> debbugs.gnu.org
Subject: Re: bug#69725: Incorrect comapration between exact and inexact numbers
Date: Mon, 18 Mar 2024 17:17:02 +0100

[Message part 1 (text/plain, inline)]
Thanks for the report! Patch attached.

regards

  Daniel



[0001-Add-missing-branch-in-scm_is_less_than.patch (application/octet-stream, attachment)]
Reply sent to lloda <lloda <at> sarc.name>:
You have taken responsibility. (Tue, 19 Mar 2024 17:31:02 GMT) Full text and rfc822 format available.
Notification sent to Maciej <m.kalandyk <at> outlook.com>:
bug acknowledged by developer. (Tue, 19 Mar 2024 17:31:02 GMT) Full text and rfc822 format available.

Message #13 received at 69725-done <at> debbugs.gnu.org (full text, mbox):

From: lloda <lloda <at> sarc.name>
To: Maciej <m.kalandyk <at> outlook.com>
Cc: 69725-done <at> debbugs.gnu.org
Subject: Re: bug#69725: Incorrect comapration between exact and inexact numbers
Date: Tue, 19 Mar 2024 18:29:48 +0100

Patch committed to 54c4753dd3f7506bee2778b36d7263b613ffd579, with a couple extra tests.

Thanks

	Daniel
bug archived. Request was from Debbugs Internal Request <help-debbugs <at> gnu.org> to internal_control <at> debbugs.gnu.org. (Wed, 17 Apr 2024 11:24:12 GMT) Full text and rfc822 format available.
This bug report was last modified 29 days ago.

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