The SQL Server ATN2()
function returns the arctangent of the two specified numbers, which is the angle between the positive x-axis and the point given by the coordinates (y, x). The result is expressed in radians and is useful in trigonometric calculations.
SELECT ATN2(y, x);
The ATN2()
function takes two arguments:
y
: The y-coordinate of the point.x
: The x-coordinate of the point.Let's look at some examples of SQL Server ATN2()
function queries:
SELECT ATN2(1, 1) AS result;
This query returns the arctangent of the point (1, 1). The result will be:
result
------
0.7853981633974483
SELECT ATN2(-1, -1) AS result;
This query returns the arctangent of the point (-1, -1). The result will be:
result
------
-2.356194490192345
SELECT y_value, x_value, ATN2(y_value, x_value) AS atan2_value
FROM coordinates;
This query returns the arctangent of the points given by the y_value
and x_value
columns for each record in the coordinates
table. The result will show the original coordinates and their corresponding arctangent as atan2_value
.
DECLARE @y FLOAT, @x FLOAT;
SET @y = 1;
SET @x = 0.5;
SELECT ATN2(@y, @x) AS result;
This query uses variables to store the coordinates and then returns their arctangent. The result will be:
result
------
1.1071487177940904
Let's go through a complete example that includes creating a table, inserting data, and using the ATN2()
function.
This step involves creating a new table named example_table
to store some sample data.
CREATE TABLE example_table (
id INT PRIMARY KEY,
y_value FLOAT,
x_value FLOAT
);
In this example, we create a table named example_table
with columns for id
, y_value
, and x_value
.
This step involves inserting some sample data into the example_table
.
INSERT INTO example_table (id, y_value, x_value) VALUES (1, 1, 1);
INSERT INTO example_table (id, y_value, x_value) VALUES (2, -1, -1);
INSERT INTO example_table (id, y_value, x_value) VALUES (3, 1, 0.5);
INSERT INTO example_table (id, y_value, x_value) VALUES (4, 0.5, 1);
Here, we insert data into the example_table
.
This step involves using the ATN2()
function to return the arctangent of the points given by the y_value
and x_value
columns.
SELECT id, y_value, x_value, ATN2(y_value, x_value) AS atan2_value
FROM example_table;
This query retrieves the id
, y_value
, x_value
, and the arctangent of the points for each row in the example_table
. The result will be:
id y_value x_value atan2_value
--- -------- -------- ------------
1 1 1 0.7853981633974483
2 -1 -1 -2.356194490192345
3 1 0.5 1.1071487177940904
4 0.5 1 0.4636476090008061
The SQL Server ATN2()
function is a powerful tool for returning the arctangent of two specified numbers, which is the angle between the positive x-axis and the point given by the coordinates (y, x). Understanding how to use the ATN2()
function and its syntax is essential for effective trigonometric calculations and data processing in SQL Server.