database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-12-19 17:02:53 +03:00
Code Activity

Add support for gamma() and lgamma() functions.

Browse Source 
These are useful general-purpose math functions which are included in
POSIX and C99, and are commonly included in other math libraries, so
expose them as SQL-callable functions.

Author: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Stepan Neretin <sncfmgg@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Dmitry Koval <d.koval@postgrespro.ru>
Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com>
Discussion: https://postgr.es/m/CAEZATCXpGyfjXCirFk9au+FvM0y2Ah+2-0WSJx7MO368ysNUPA@mail.gmail.com
This commit is contained in:
Dean Rasheed
2025-03-26 09:35:53 +00:00
parent 7c82b4f711
commit a3b6dfd410
6 changed files with 214 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

57
src/test/regress/expected/float8.out
View File

@@ -829,6 +829,63 @@ FROM (VALUES (float8 '-infinity'),
NaN | NaN | NaN
(22 rows)
RESET extra_float_digits;
-- gamma functions
-- we run these with extra_float_digits = -1, to get consistently rounded
-- results on all platforms.
SET extra_float_digits = -1;
SELECT x,
gamma(x),
lgamma(x)
FROM (VALUES (0.5), (1), (2), (3), (4), (5),
(float8 'infinity'), (float8 'nan')) AS t(x);
x | gamma | lgamma
----------+-----------------+------------------
0.5 | 1.7724538509055 | 0.5723649429247
1 | 1 | 0
2 | 1 | 0
3 | 2 | 0.69314718055995
4 | 6 | 1.7917594692281
5 | 24 | 3.1780538303479
Infinity | Infinity | Infinity
NaN | NaN | NaN
(8 rows)
-- test overflow/underflow handling
SELECT gamma(float8 '-infinity');
ERROR: value out of range: overflow
SELECT lgamma(float8 '-infinity');
lgamma
----------
Infinity
(1 row)
SELECT gamma(float8 '-1000.5');
ERROR: value out of range: underflow
SELECT lgamma(float8 '-1000.5');
lgamma
------------------
-5914.4377011169
(1 row)
SELECT gamma(float8 '-1');
ERROR: value out of range: overflow
SELECT lgamma(float8 '-1');
ERROR: value out of range: overflow
SELECT gamma(float8 '0');
ERROR: value out of range: overflow
SELECT lgamma(float8 '0');
ERROR: value out of range: overflow
SELECT gamma(float8 '1000');
ERROR: value out of range: overflow
SELECT lgamma(float8 '1000');
lgamma
-----------------
5905.2204232092
(1 row)
SELECT lgamma(float8 '1e308');
ERROR: value out of range: overflow
RESET extra_float_digits;
-- test for over- and underflow
INSERT INTO FLOAT8_TBL(f1) VALUES ('10e400');

23
src/test/regress/sql/float8.sql
View File

@@ -245,6 +245,29 @@ FROM (VALUES (float8 '-infinity'),
RESET extra_float_digits;
-- gamma functions
-- we run these with extra_float_digits = -1, to get consistently rounded
-- results on all platforms.
SET extra_float_digits = -1;
SELECT x,
gamma(x),
lgamma(x)
FROM (VALUES (0.5), (1), (2), (3), (4), (5),
(float8 'infinity'), (float8 'nan')) AS t(x);
-- test overflow/underflow handling
SELECT gamma(float8 '-infinity');
SELECT lgamma(float8 '-infinity');
SELECT gamma(float8 '-1000.5');
SELECT lgamma(float8 '-1000.5');
SELECT gamma(float8 '-1');
SELECT lgamma(float8 '-1');
SELECT gamma(float8 '0');
SELECT lgamma(float8 '0');
SELECT gamma(float8 '1000');
SELECT lgamma(float8 '1000');
SELECT lgamma(float8 '1e308');
RESET extra_float_digits;
-- test for over- and underflow
INSERT INTO FLOAT8_TBL(f1) VALUES ('10e400');