EV(1)
NAME
ev - evaluate expressions
SYNOPSIS
ev 'expr' ..
DESCRIPTION
- Ev evaluates expressions given on the command line, and sends the
results to the standard output, one per line. An expression contains
real numbers, function calls, and the following operators:
- + - * / ^
- Operators are evaluated left to right, except '^', which is right associative. Powers have the highest precedence; multiplication and division are evaluated before addition and subtraction. Expressions can be grouped with parentheses. All values are double precision real.
- The following library of functions is available:
- if(cond, then, else)
- if cond is greater than zero, then is evaluated, otherwise else is evaluated.
- select(N, a1, a2, ..)
- return aN (N is rounded to the nearest integer). If N is zero, the number of available arguments is returned.
- rand(x) compute a random number between 0 and 1 based on x.
- floor(x) return largest integer not greater than x.
- ceil(x) return smallest integer not less than x.
- sqrt(x) return square root of x.
- exp(x) compute e to the power of x (e approx = 2.718281828).
- log(x) compute the logarithm of x to the base e.
- log10(x) compute the logarithm of x to the base 10.
- sin(x), cos(x), tan(x)
- trigonometric functions.
- asin(x), acos(x), atan(x)
- inverse trigonometric functions.
- atan2(y, x)
- inverse tangent of y/x (range -pi to pi).
EXAMPLE
- To pass the square root of two and the sine of .5 to a program:
- program `ev 'sqrt(2)' 'sin(.5)'`
AUTHOR
Greg Ward