CORR¶
Returns the Pearson correlation coefficient of value pairs.
Syntax¶
-- As an aggregate
CORR( expr1, expr2 )
-- As a window function
CORR ( expr1, expr2 ) OVER (
[ PARTITION BY partition_expr [, ...] ]
[ ORDER BY order [ ASC | DESC ] [, ...]]
)
Arguments¶
Parameter | Description |
---|---|
expr1 , expr2 |
Numeric expression |
Returns¶
Returns the Perason correlation coefficient with type DOUBLE
.
Notes¶
- When all rows contain
NULL
values, the function returnsNULL
.
Examples¶
For these examples, assume a table named nba
, with the following structure:
CREATE TABLE nba
(
"Name" varchar(40),
"Team" varchar(40),
"Number" tinyint,
"Position" varchar(2),
"Age" tinyint,
"Height" varchar(4),
"Weight" real,
"College" varchar(40),
"Salary" float
);
Here’s a peek at the table contents (Download nba.csv
):
Name | Team | Number | Position | Age | Height | Weight | College | Salary |
---|---|---|---|---|---|---|---|---|
Avery Bradley | Boston Celtics | 0.0 | PG | 25.0 | 6-2 | 180.0 | Texas | 7730337.0 |
Jae Crowder | Boston Celtics | 99.0 | SF | 25.0 | 6-6 | 235.0 | Marquette | 6796117.0 |
John Holland | Boston Celtics | 30.0 | SG | 27.0 | 6-5 | 205.0 | Boston University | |
R.J. Hunter | Boston Celtics | 28.0 | SG | 22.0 | 6-5 | 185.0 | Georgia State | 1148640.0 |
Jonas Jerebko | Boston Celtics | 8.0 | PF | 29.0 | 6-10 | 231.0 | 5000000.0 | |
Amir Johnson | Boston Celtics | 90.0 | PF | 29.0 | 6-9 | 240.0 | 12000000.0 | |
Jordan Mickey | Boston Celtics | 55.0 | PF | 21.0 | 6-8 | 235.0 | LSU | 1170960.0 |
Kelly Olynyk | Boston Celtics | 41.0 | C | 25.0 | 7-0 | 238.0 | Gonzaga | 2165160.0 |
Terry Rozier | Boston Celtics | 12.0 | PG | 22.0 | 6-2 | 190.0 | Louisville | 1824360.0 |
Simple correlation¶
t=> SELECT "Team", CORR("Age","Salary") FROM nba GROUP BY 1 ORDER BY 2 ASC;
Team | corr
-----------------------+--------
Cleveland Cavaliers | -0.3219
San Antonio Spurs | -0.2015
Oklahoma City Thunder | -0.1236
Detroit Pistons | -0.0678
New Orleans Pelicans | -0.0459
Los Angeles Clippers | -0.0279
Utah Jazz | 0.0913
Washington Wizards | 0.1217
Dallas Mavericks | 0.1388
Sacramento Kings | 0.1489
Milwaukee Bucks | 0.1626
Golden State Warriors | 0.1648
Minnesota Timberwolves | 0.1909
Denver Nuggets | 0.2035
Houston Rockets | 0.2051
Philadelphia 76ers | 0.2645
Chicago Bulls | 0.2663
Phoenix Suns | 0.2808
Orlando Magic | 0.2878
Toronto Raptors | 0.2916
Memphis Grizzlies | 0.3225
Miami Heat | 0.3635
Charlotte Hornets | 0.3779
Brooklyn Nets | 0.4084
Indiana Pacers | 0.4261
Atlanta Hawks | 0.4321
New York Knicks | 0.4401
Los Angeles Lakers | 0.4563
Portland Trail Blazers | 0.4856
Boston Celtics | 0.6904