agora inbox for pgsql-sql@postgresql.org  

help / color / mirror / Atom feed

From: Max Lipsky <maxlipsky@gmail.com>
To: pgsql-sql@lists.postgresql.org
Subject: Problem in
Date: Thu, 25 Apr 2019 16:45:18 +0300
Message-ID: <2164C531-EAA3-4CAF-996F-FEB0E5F73B32@gmail.com> (raw)

Hi everyone!

I found an incomprehensible behavior of some functions in PostgreSQL 9.5.12 (for 10.6 working good). 

For example:

SELECT acos(
           cos(radians(48.9193))
           * cos(radians(48.9193))
           * cos(radians(2.5431) - radians(2.5431))
           + sin(radians(48.9193))
             * sin(radians(48.9193))
       ) as result;

This returned [22003] ERROR: input is out of range

But this one working good:

SELECT acos(
           cos(radians(48.9192))
           * cos(radians(48.9192))
           * cos(radians(2.5431) - radians(2.5431))
           + sin(radians(48.9192))
             * sin(radians(48.9192))
       ) as result;

The difference is 48.9193 => 48.9192

I did research a bit and found what this query

SELECT cos(0.8538028527708621) * cos(0.8538028527708621) + sin(0.8538028527708621) * sin(0.8538028527708621) as s1;
Returned 1.0000000000000002

SELECT cos(0.8538028527708621) * cos(0.8538028527708621) as s1; -- 0.43180849723816966
SELECT sin(0.8538028527708621) * sin(0.8538028527708621) as s1; -- 0.5681915027618305
Looks like cos() have scale = 17 (sometimes), but sin() have scale 16



P.S. I saw it only in the IntelliJ IDEA console. In the native console these values will be rounded:

SELECT cos(0.8538028527708621) * cos(0.8538028527708621) as s1;
        s1
------------------
 0.43180849723817



* * *
Best Regards,
Max Lipsky

view thread (9+ messages)  latest in thread

Message-ID: <2164C531-EAA3-4CAF-996F-FEB0E5F73B32@gmail.com>
Permalink:  ../2164C531-EAA3-4CAF-996F-FEB0E5F73B32@gmail.com/
Also on:    postgresql.org/message-id/2164C531-EAA3-4CAF-996F-FEB0E5F73B32@gmail.com

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-sql@postgresql.org
  Cc: maxlipsky@gmail.com, pgsql-sql@lists.postgresql.org
  Subject: Re: Problem in
  In-Reply-To: <2164C531-EAA3-4CAF-996F-FEB0E5F73B32@gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox