Trigonometric functions

This page describes the available functions to assist with performing trigonometric calculations.

tip

Positive and negative infinity values are expressed as 'Infinity' or '-Infinity' in QuestDB.

acos

acos(value) returns the arccosine of a value.

Arguments

• value is a numeric value whose arccosine is to be returned. The returned angle is between 0.0 and pi inclusively.

Return value

Return value type is double.

Description

Special cases: if the argument is NaN or its absolute value is greater than 1, then the result is Null.

Examples

SELECT acos(0.0) acos;

acos
1.570796326794

asin

asin(value) the arcsine of a value.

Arguments

• value is a numeric value whose arcsine is to be returned.

Return value

Return value type is double. The returned angle is between -pi/2 and pi/2 inclusively.

Description

Special case: if the argument is NaN or an infinity, then the result is Null.

Examples

SELECT asin(1.0) asin;

asin
1.570796326794

atan

atan(value) returns the arctangent of a value.

Arguments

• value is a numeric value whose arctangent is to be returned.

Return value

Return value type is double. The returned angle is between -pi/2 and pi/2 inclusively.

Description

Special cases:

• If the argument is NaN, then the result is Null.
• If the argument is infinity, then the result is the closest value to pi/2 with the same sign as the input.

Examples

Special case where input is '-Infinity':

SELECT atan('-Infinity');

Returns the closest value to pi/2 with the same sign as the input:

atan
-1.570796326794

SELECT atan(1.0) atan;

atan
0.785398163397

atan2

atan2(valueY, valueX) returns the angle theta from the conversion of rectangular coordinates (x, y) to polar (r, theta). This function computes theta (the phase) by computing an arctangent of y/x in the range of -pi to pi inclusively.

Arguments

• valueY numeric ordinate coordinate.
• valueX numeric abscissa coordinate.

note

The arguments to this function pass the y-coordinate first and the x-coordinate second.

Return value

Return value type is double between -pi and pi inclusively.

Description:

atan2(valueY, valueX) measures the counterclockwise angle theta, in radians, between the positive x-axis and the point (x, y):

Special cases:

input valueY	input valueX	atan2 return value
0	Positive value	0
Positive finite value	'Infinity'	0
-0	Positive value	0
Negative finite value	'Infinity'	0
0	Negative value	Double value closest to pi
Positive finite value	'-Infinity'	Double value closest to pi
-0	Negative value	Double value closest to -pi
Negative finite value	'-Infinity'	Double value closest to -pi
Positive value	0 or -0	Double value closest to pi/2
'Infinity'	Finite value	Double value closest to pi/2
Negative value	0 or -0	Double value closest to -pi/2
'-Infinity'	Finite value	Double value closest to -pi/2
'Infinity'	'Infinity'	Double value closest to pi/4
'Infinity'	'-Infinity'	Double value closest to 3/4 * pi
'-Infinity'	'Infinity'	Double value closest to -pi/4
'-Infinity'	'-Infinity'	Double value closest to -3/4 * pi

Examples

SELECT atan2(1.0, 1.0) atan2;

atan2
0.785398163397

cos

cos(angleRadians) returns the trigonometric cosine of an angle.

Arguments

• angleRadians numeric value for the angle, in radians.

Return value

Return value type is double.

Description

Special case: if the argument is NaN or an infinity, then the result is Null.

Examples

SELECT pi()/2 angle, cos(pi()/2) cos;

angle	cos
1.570796326794	6.123233995736766e-17

cot

cot(angleRadians) returns the trigonometric cotangent of an angle.

Arguments

• angleRadians numeric value for the angle, in radians.

Return value

Return value type is double.

Description

Special case: if the argument is NaN, 0, or an infinity, then the result is Null.

Examples

SELECT pi()/2 angle, cot(pi()/2) cot;

angle	cot
1.570796326794	6.123233995736766e-17

degrees

degrees(angleRadians) converts an angle measured in radians to the equivalent angle measured in degrees.

Arguments

• angleRadians numeric value for the angle in radians.

Return value

Return value type is double.

Examples

SELECT degrees(pi());

degrees
180

pi

pi() returns the constant pi as a double.

Arguments

None.

Return value

Return value type is double.

Examples

SELECT pi();

pi
3.141592653589

radians

radians(angleDegrees) converts an angle measured in degrees to the equivalent angle measured in radians.

Arguments

• angleDegrees numeric value for the angle in degrees.

Return value

Return value type is double.

Examples

SELECT radians(180);

radians
3.141592653589

sin

sin(angleRadians) returns the trigonometric sine of an angle.

Arguments

• angleRadians is a numeric value indicating the angle in radians.

Return value

Return value type is double.

Description

Special case: if the argument is NaN or an infinity, then the result is Null.

Examples

SELECT pi()/2 angle, sin(pi()/2) sin;

angle	sin
1.570796326794	1

tan

tan(angleRadians) returns the trigonometric tangent of an angle.

Arguments

• angleRadians numeric value for the angle, in radians.

Return value

Return value type is double.

Description

Special case: if the argument is NaN or an infinity, then the result is Null.

Examples

SELECT pi()/2 angle, tan(pi()/2) tan;

angle	tan
1.570796326794	16331239353195370