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Standard mathematical and trigonometric functions.
Trigonometric functions work with angles in radians.

sin( theta )
 Sine of an angle.

cos( theta )
 Cosine of an angle.

tan( theta )
 Tangent of an angle.

asin( x )
 Arc sine of an angle.
The result is in the range of pi/2 through
pi/2.

acos( x )
 Arc cosine of an angle.
The result is in the range of 0.0 through pi.

atan( x )
 Arc tangent of an angle.
The result is in the range of pi/2 through pi/2.

exp( x )
 Euler's number e raised to a power.

log10( x )
 Logarithm to base 10.

ln( x )
 Natural logarithm.

sqrt( x )
 Square root.
The result is correctly rounded and positive.

hypot( xs, ... )
 Returns the square root of the sum of squares of its arguments.
In the 2argument case, doing it like this may avoid intermediate
overflow or underflow.

atan2( y, x )
 Converts rectangular coordinates (
x
,y
)
to polar (r
,theta
).
This method computes the phase
theta
by computing an arc tangent
of y/x
in the range of pi to pi.

pow( a, b )
 Exponentiation.
The result is the value of the first argument raised to
the power of the second argument.

sinh( x )
 Hyperbolic sine.

cosh( x )
 Hyperbolic cosine.

tanh( x )
 Hyperbolic tangent.

asinh( x )
 Inverse hyperbolic sine.

acosh( x )
 Inverse hyperbolic cosine.

atanh( x )
 Inverse hyperbolic tangent.

E
 Euler's number e, the base of natural logarithms.

PI

Pi, the ratio of the circumference of a circle to its diameter.

Infinity
 Positive infinite floating point value.

NaN
 NotaNumber floating point value.
Use with care; arithmetic and logical operations behave in strange
ways near NaN (for instance,
NaN!=NaN
).
For most purposes this is equivalent to the blank value.

RANDOM
 Evaluates to a random number in the range 0<=x<1.
This is different for each cell of the table.
The quality of the randomness may not be particularly good.
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TOPCAT  Tool for OPerations on Catalogues And Tables
Starlink User Note253
TOPCAT web page:
http://www.starlink.ac.uk/topcat/
Author email:
m.b.taylor@bristol.ac.uk
Mailing list:
topcatuser@jiscmail.ac.uk