In PostgreSQL, the scale() function returns the scale of its argument.
The scale is the number of decimal digits in the fractional part.
Continue readingTag: mathematical functions
How the Sign() Function Works in PostgreSQL
In PostgreSQL, the sign() function is used to indicate the sign of its argument.
It doesn’t simply return the actual sign. Rather, it returns -1 for negative numbers, 0 for zero, and 1 for positive numbers.
Continue readingHow cbrt() Works in PostgreSQL
In PostgreSQL, the cbrt() function returns the cube root of its argument.
The cube root of a number x is a number y such that y3 = x.
Continue readingHow sqrt() Works in PostgreSQL
In PostgreSQL, the sqrt() function returns the square root of its argument.
The square root of a number x is the number y such that y2 = x.
Continue readingHow Abs() Works in PostgreSQL
In PostgreSQL, the abs() function returns the absolute value of its argument.
The absolute value means how far the number is away from zero. Therefore, the absolute value of 7 is 7, and the absolute value of -7 is also 7.
Therefore, any negative values passed to abs() are returned as positive values. Positive values and zero are returned unchanged.
How Setseed() Works in PostgreSQL
In PostgreSQL, the setseed() function sets the seed for subsequent random() and random_normal() calls (value between -1.0 and 1.0, inclusive).
The random() function generates a pseudo-random number using a simple linear congruential algorithm. The random_normal() function generates a normally-distributed random number.
If setseed() is called, the results of subsequent random() and random_normal() calls in the current session are repeatable by re-issuing setseed() with the same argument.
How Random() Works in PostgreSQL
In PostgreSQL, the random() function returns a pseudo-random value in the range 0.0 <= x < 1.0.
It uses a simple linear congruential algorithm, which is one of the oldest and best-known pseudo-random number generator algorithms.
A pseudo-random number is a number that appears to be random, but is not truely random. A pseudo-random number is not truely random because its value was generated by a known seed. However, it will appear to be random if the user has no knowledge of the seed or algorithm that created it.
Therefore, pseudo-random numbers are often considered good enough for many applications.
Continue readingHow Cot() Works in PostgreSQL
In PostgreSQL, cot() is a trigonometric function that returns the cotangent of the specified angle.
The angle is provided as an argument, specified in radians.
In trigonometry, in a right triangle, the cotangent of an angle is the length of the adjacent side divided by the length of the opposite side.
Continue readingHow Cotd() Works in PostgreSQL
In PostgreSQL, cotd() is a trigonometric function that returns the cotangent of the specified angle.
The angle is provided as an argument, specified in degrees.
In trigonometry, in a right triangle, the cotangent of an angle is the length of the adjacent side divided by the length of the opposite side.
Continue readingHow Atan2() Works in PostgreSQL
In PostgreSQL, atan2() is a trigonometric function that returns the arctangent, or inverse tangent, of the specified x and y coordinates in radians.