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greg |
1.4 |
.\" RCSid "$Id: ev.1,v 1.3 2004/01/01 19:31:44 greg Exp $"
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greg |
1.1 |
.TH EV 1 10/28/96 RADIANCE
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.SH NAME
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ev - evaluate expressions
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.SH SYNOPSIS
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.B ev 'expr' ..
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.SH DESCRIPTION
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.I Ev
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evaluates expressions given on the command line, and sends the
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results to the standard output, one per line.
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An expression contains real numbers, function calls,
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and the following operators:
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.PP
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+ - * / ^
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.PP
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Operators are evaluated left to right, except '^',
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which is right associative.
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Powers have the highest precedence; multiplication and
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division are evaluated before addition and subtraction.
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Expressions can be grouped with parentheses.
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All values are double precision real.
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.PP
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The following library of functions is available:
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.TP 10n
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.BR "if(cond, then, else)"
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if cond is greater than zero,
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then is evaluated, otherwise else is evaluated.
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.TP
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.BR "select(N, a1, a2, ..)"
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return aN (N is rounded to the nearest integer).
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If
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.I N
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is zero, the number of available arguments is returned.
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.TP
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.BR "rand(x)"
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compute a random number between 0 and 1 based on x.
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.TP
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.BR "floor(x)"
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return largest integer not greater than x.
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.TP
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.BR "ceil(x)"
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return smallest integer not less than x.
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.TP
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.BR "sqrt(x)"
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return square root of x.
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.TP
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.BR "exp(x)"
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compute e to the power of x (e approx = 2.718281828).
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.TP
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.BR "log(x)"
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compute the logarithm of x to the base e.
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.TP
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.BR "log10(x)"
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compute the logarithm of x to the base 10.
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.TP
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.BR "sin(x), cos(x), tan(x)"
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trigonometric functions.
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.TP
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.BR "asin(x), acos(x), atan(x)"
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inverse trigonometric functions.
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.TP
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.BR "atan2(y, x)"
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greg |
1.4 |
inverse tangent of y/x (range \-pi to pi).
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greg |
1.1 |
.SH EXAMPLE
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To pass the square root of two and the sine of .5 to a program:
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.IP "" .2i
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program `ev 'sqrt(2)' 'sin(.5)'`
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.SH AUTHOR
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Greg Ward
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.SH "SEE ALSO"
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greg |
1.3 |
icalc(1), rcalc(1)
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