Acronym for Multiple Precision Arithmetics. Library in pure Tcl available at : http://sarnold.free.fr/
Examples
with a 333MHz PII 100MHz PCI Bus PC with Windows Me.
(mpa-v0.11) 50 % package require mpa 0.11 (mpa-v0.11) 51 % mpa::int::add 111111111111111111111 98237827463784678346478 98348938574895789457589 (mpa-v0.11) 52 % mpa::int::add 1000000000000000000000 99999999999999999 1000099999999999999999 (mpa-v0.11) 53 % mpa::int::mul 1001 9009 9018009 (mpa-v0.11) 54 % mpa::int::mul 10010001 9009009 90180189099009 (mpa-v0.11) 55 % mpa::float::pi 20 # Pi constant with 20 decimals, the result is cached in a namespace variable 3.14159265358979323846 (mpa-v0.11) 56 % time {mpa::float::pi 20};# result is cached in memory 363 microseconds per iteration (mpa-v0.11) 57 % time {mpa::float::pi 21};# result is now recomputed 90643 microseconds per iteration (mpa-v0.11) 58 % time {puts [mpa::float::pi 21]};# result is cached 3.141592653589793238462 4962 microseconds per iteration (mpa-v0.11) 59 % mpa::float::add 1.0 2.0 3.0~2 # the precision with 1.0 ans 2.0 is assumed to be 0.1 # and the precision of the sum is the sum of the precisions (mpa-v0.11) 60 % mpa::float::add 1.0000 2.0000 3.0000~2 (mpa-v0.11) 62 % mpa::float::format [mpa::float::mul 1.0000000 2.0000000]; # the precision of the product is approximatly A*Pb+B*Pa = 3e-7 2.000000 # now the number is formatted to be put on screen (mpa-v0.11) 63 % mpa::float::mul 1.0000000 2.0000000 2.0000000~4 # precision is computed to be always the smallest , # even if such computations are complex to handle and loss of CPU
This package is especially good when you want it to represent numbers as strings. In fact, MPA is built upon the principle that everything is a string in Tcl. For binary computations (e.g. crypto algorithms) you can see a better pure-tcl lib in bignum in pure Tcl.