druid/docs/content/misc/math-expr.md

layout
doc_page

This expression language supports the following operators (listed in decreasing order of precedence).

Operators	Description
!, -	Unary NOT and Minus
^	Binary power op
*, /, %	Binary multiplicative
+, -	Binary additive
<, <=, >, >=, ==, !=	Binary Comparison
&&,||	Binary Logical AND, OR

Long and double data types are supported. If a number contains a dot, it is interpreted as a double, otherwise it is interpreted as a long. That means, always add a '.' to your number if you want it intepreted as a double value.

Expressions can contain variables. Variable names may contain letters, digits, '_' and '$'. Variable names must not begin with a digit.

For logical operators, a number is true if and only if it is positive. (0 means false)

Also, the following in-built functions are supported.

name	description
sqrt	sqrt(x) would return square root of x
if	if(predicate,then,else) returns 'then' if 'predicate' evaluates to a positive number, otherwise it returns 'else'

Built-in Math functions. See javadoc of java.lang.Math for detailed explanation for each function.

|abs|abs(x) would return the absolute value of x| |acos|acos(x) would return the arc cosine of x| |asin|asin(x) would return the arc sine of x| |atan|atan(x) would return the arc tangent of x| |atan2|atan2(y, x) would return the angle theta from the conversion of rectangular coordinates (x, y) to polar * coordinates (r, theta)| |cbrt|cbrt(x) would return the cube root of x| |ceil|ceil(x) would return the smallest (closest to negative infinity) double value that is greater than or equal to x and is equal to a mathematical integer| |copysign|copysign(x) would return the first floating-point argument with the sign of the second floating-point argument| |cos|cos(x) would return the trigonometric cosine of x| |cosh|cosh(x) would return the hyperbolic cosine of x| |exp|exp(x) would return Euler's number raised to the power of x| |expm1|expm1(x) would return e^x-1| |floor|floor(x) would return the largest (closest to positive infinity) double value that is less than or equal to x and is equal to a mathematical integer| |getExponent|getExponent(x) would return the unbiased exponent used in the representation of x| |hypot|hypot(x, y) would return sqrt(x^2+y^2) without intermediate overflow or underflow| |log|log(x) would return the natural logarithm of x| |log10|log10(x) would return the base 10 logarithm of x| |log1p|log1p(x) would the natural logarithm of x + 1| |max|max(x, y) would return the greater of two values| |min|min(x, y) would return the smaller of two values| |nextafter|nextafter(x, y) would return the floating-point number adjacent to the x in the direction of the y| |nextUp|nextUp(x) would return the floating-point value adjacent to x in the direction of positive infinity| |pow|pow(x, y) would return the value of the x raised to the power of y| |remainder|remainder(x, y) would return the remainder operation on two arguments as prescribed by the IEEE 754 standard| |rint|rint(x) would return value that is closest in value to x and is equal to a mathematical integer| |round|round(x) would return the closest long value to x, with ties rounding up| |scalb|scalb(d, sf) would return d * 2^sf rounded as if performed by a single correctly rounded floating-point multiply to a member of the double value set| |signum|signum(x) would return the signum function of the argument x| |sin|sin(x) would return the trigonometric sine of an angle x| |sinh|sinh(x) would return the hyperbolic sine of x| |sqrt|sqrt(x) would return the correctly rounded positive square root of x| |tan|tan(x) would return the trigonometric tangent of an angle x| |tanh|tanh(x) would return the hyperbolic tangent of x| |todegrees|todegrees(x) converts an angle measured in radians to an approximately equivalent angle measured in degrees| |toradians|toradians(x) converts an angle measured in degrees to an approximately equivalent angle measured in radians| |ulp|ulp(x) would return the size of an ulp of the argument x|