Table of Contents

ev - evaluate expressions

**ev** **`expr'** **..**

*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. 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).

To pass the square root of two and the sine of .5 to a
program:
program `ev `sqrt(2)' `sin(.5)'`

Greg Ward

calc(1), rcalc(1)

## Header and Footer

EV(1) RADIANCE (11/15/93) EV(1)

Page 1 (printed 7/17/96)

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