IoT Platform:Mathematical functions

double abs(double <number>)
bigint abs(bigint <number>)
decimal abs(decimal <number>)

Calculates the absolute value of number.

The type of the return value depends on that of the input value, which can be DOUBLE, BIGINT, or DECIMAL.

-- The return value is NULL. 
    abs(null);

-- The return value is 1. 
    abs(-1);

-- The return value is 1.2. 
    abs(-1.2);

-- The return value is 2.0. 
    abs("-2");

-- The value 1.2232083745629837E32 is returned. 
    abs(122320837456298376592387456923748);

double asin(double <number>)
decimal asin(decimal <number>)

Calculates the arcsine of number.

number: required. The value is of the DOUBLE or DECIMAL type and ranges from -1 to 1. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. The value ranges from -π/2 to π/2. If the input parameter is set to null, null is returned.

--The return value is 1.5707963267948966. 
    asin(1);
-- The return value is 1.5707963267948966. 
    asin(-1);

bigint ceil(double <value>)
bigint ceil(decimal <value>)

Rounds up value and returns the nearest integer.

value: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the BIGINT type is returned. If the input parameter is set to null, null is returned.

-- The return value is 2. 
    ceil(1.1);
-- The return value is -1. 
    ceil(-1.1);

double cos(double <number>)
decimal cos(decimal <number>)

Calculates the cosine of number, which is a radian value.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is 2.6794896585028633e-8. 
    cos(3.1415926/2);

-- The return value is -0.9999999999999986. 
    cos(3.1415926);

double cosh(double <number>)
decimal cosh(decimal <number>)

Calculates the hyperbolic cosine of number.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is 2.5091784169949913. 
    cosh(3.1415926/2);

double exp(double <number>)
decimal exp(decimal <number>)

Calculates the exponential value of number.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is 4.810477252069109. 
    exp(3.1415926/2);

bigint floor(double <number>)
bigint floor(decimal <number>)

Rounds down number and returns the nearest integer that is no greater than the value of number.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the BIGINT type is returned. If the input parameter is set to null, null is returned.

-- The return value is 1. 
    floor(1.2);

-- The return value is 0. 
    floor(0.1);

-- The return value is -2. 
    floor(-1.2);

-- The return value is -1. 
    floor(-0.1);

-- The return value is 0. 
    floor(0.0);

-- The return value is 0. 
    floor(-0.0);

double log(double <base>, double <x>)
decimal log(decimal <base>, decimal <x>)

Calculates the logarithm of x whose base number is base.

• base: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.
• x: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

-- The return value is 4.0. 
    log(2, 16);

double pow(double <x>, double <y>)
decimal pow(decimal <x>, decimal <y>)

Calculates the yth power of x, namely, ^{x^y}.

• x: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.
• y: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If an input parameter is set to null, null is returned.

-- The return value is 65536.0. 
    pow(2, 16);

double rand(bigint <seed>)

Returns a random number of the DOUBLE type. The value ranges from 0 to 1.

seed: optional. The value is of the BIGINT type. This parameter specifies the random seed that determines the starting point in generating random numbers.

A value of the DOUBLE type is returned.

-- The rerturn value is 4.7147460303803655E-4. 
    rand();
-- The return value is 0.7308781907032909. 
    rand(1);

double round(double <number>[, bigint <decimal_places>])
decimal round(decimal <number>[, bigint <decimal_places>])

Returns a number rounded to the specified decimal place.

• number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.
• decimal_places: optional. The value is a constant of the BIGINT type. The value is rounded to the specified decimal place. If it is of another data type, an error is returned. If this parameter is not specified, the number is rounded to the ones place. The default value is 0.
  Note The value of decimal_places can be negative. A negative value indicates counting from the decimal point to the left, and the decimal part is excluded. If decimal_places exceeds the length of the integer part, 0 is returned.

A value of the DOUBLE or DECIMAL type is returned. If an input parameter is set to null, null is returned.

-- The return value is 125.0. 
    round(125.315);
-- The return value is 125.3. 
    round(125.315, 1);
-- The return value is 125.32. 
    round(125.315, 2);
-- The return value is 125.315. 
    round(125.315, 3);
-- The return value is -125.32. 
    round(-125.315, 2);
-- The return value is 100.0. 
    round(123.345, -2);
-- The return value is null. 
    round(null);
-- The return value is 123.345. 
    round(123.345, 4);
-- The return value is 0.0. 
    round(123.345, -4);

double sin(double <number>)
decimal sin(decimal <number>)

Calculates the sine of number, which is a radian value.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is -0.3048106211022167. 
    sin(60);

double sinh(double <number>)
decimal sinh(decimal <number>)

Calculates the hyperbolic sine of number.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is 5.343237290762231E12. 
    sinh(30);

double sqrt(double <number>)
decimal sqrt(decimal <number>)

Calculates the square root of number.

number: required. If the input value is of the DOUBLE or DECIMAL type, the value must be greater than 0. Otherwise, an exception is returned. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is 2.0. 
    sqrt(4);

double tan(double <number>)
decimal tan(decimal <number>)

Calculates the tangent of number, which is a radian value.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is -6.405331196646276. 
    tan(30);

double tanh(double <number>)
decimal tanh(decimal <number>)

Calculates the hyperbolic tangent of number.

number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.

A value of the DOUBLE or DECIMAL type is returned. If the input parameter is set to null, null is returned.

-- The return value is 1.0. 
tanh(30);

double trunc(double <number>[, bigint <decimal_places>])
decimal trunc(decimal <number>[, bigint <decimal_places>])

Truncates the input value of number to the specified decimal place.

• number: required. A value of the DOUBLE or DECIMAL type. If the input value is of the STRING or BIGINT type, it is implicitly converted into a value of the DOUBLE type before the calculation. If the input value is of another data type, an error is returned.
• decimal_places: optional. The value is a constant of the BIGINT type. This parameter specifies the position where the number is truncated. If the value is of another data type, it is converted into a value of the BIGINT type. If this parameter is not specified, the number is truncated to the ones place.
  Note decimal_places can be a negative value, which indicates that the number is truncated from the decimal point to the left and the decimal part is left out. If decimal_places exceeds the length of the integer part, 0 is returned.

A value of the DOUBLE or DECIMAL type is returned. If an input parameter is set to null, null is returned.

-- The return value is 125.0. 
    trunc(125.815,0);
-- The return value is 125.80000000000001. 
    trunc(125.815,1);
-- The return value is 125.81. 
    trunc(125.815,2);
-- The return value is 125.815. 
    trunc(125.815,3);
-- The return value is -125.81. 
    trunc(-125.815,2);
-- The return value is 120.0. 
    trunc(125.815,-1);
-- The return value is 100.0. 
    trunc(125.815,-2);
-- The return value is 0.0. 
    trunc(125.815,-3);
-- The return value is 123.345. 
    trunc(123.345,4);
-- The return value is 0.0. 
    trunc(123.345,-4);

string hex(bigint <number>) 
string hex(string <number>)
string hex(binary <number>)

Converts an integer or a string to a hexadecimal number.

number: required. If number is of the BIGINT type, a hexadecimal number is returned. If number is of the STRING type, a string in the hexadecimal format is returned.

• If the input value is not 0 or null, a value of the STRING type is returned.
• If the input value is 0, 0 is returned.
• If the input value is set to null, an error is returned.

--The return value is 0. 
    hex(0);
-- The return value is 616263. 
    hex('abc');
-- The return value is 11. 
    hex(17);
-- The return value is 3137. 
    hex('17');
-- An error is returned.  
    hex(null);

binary unhex(string <number>)

Converts a hexadecimal string into a string.

number: required. The value is a hexadecimal string.

A value of the BINARY type is returned. If the input value is 0, an error is returned. If the input parameter is set to null, null is returned.

--The return value is abc 
    unhex('616263');
-- The return value is abc. 
    unhex(616263);

double pi()

Calculates the value of π.

A value of the DOUBLE type is returned.

-- The return value is 3.141592653589793. 
    pi();