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Standard mathematical and trigonometric functions.
-
E
- Euler's number e, the base of natural logarithms.
-
PI
-
Pi, the ratio of the circumference of a circle to its diameter.
-
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.
-
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.
-
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.
Next Previous Up Contents
Next: Conversions
Up: General Functions
Previous: Times
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:
topcat-user@bristol.ac.uk