Package: tcllib, Version: CVS HEAD
math::constants -
Mathematical and numerical constants
package require Tcl ? 8.3 ? package require math::constants ? 1.0.1 ? ::math::constants::constants args ::math::constants::print-constants args
This package defines some common mathematical and numerical constants. By using the package you get consistent values for numbers like pi and ln(10).
It defines two commands:
The motivation for this package is that quite often, with (mathematical) computations, you need a good approximation to, say, the ratio of degrees to radians. You can, of course, define this like:
variable radtodeg [expr {180.0/(4.0*atan(1.0))}]and use the variable radtodeg whenever you need the conversion.
This has two drawbacks:
package require math::constants ::math::constants::constants radtodeg degtoradwhich creates two variables, radtodeg and (its reciprocal) degtorad in the calling namespace.
Constants that have been defined (their values are mostly taken from mathematical tables with more precision than usually can be handled) include:
set value [expr {3.0*$onethird}]give exactly the value you expect (if IEEE arithmetic is available).