| # The bcmath library |
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| This is a fork of the bcmath library initially created by Phil Nelson in May |
| 2000. |
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| Bcmath is a library of arbitrary precision math routines. These routines, in a |
| different form, are the routines that to the arbitrary precision calculations |
| for GNU bc and GNU dc. |
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| This library is provided to make these routines useful in a larger context with |
| less restrictions on the use of them. |
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| These routines do not duplicate functionality of the GNU gmp library. The gmp |
| library is similar, but the actual computation is different. |
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| Initial library (version 0.1) has been created in 2000-05-21 and then forked and |
| bundled into PHP with version 0.2 released in 2000-06-07. |
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| ## FAQ |
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| * Why BCMATH? |
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| The math routines of GNU bc become more generally useful in a library form. By |
| separating the BCMATH library from GNU bc, GNU bc can be under the GPL and |
| BCMATH can be under the LGPL. |
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| * Why BCMATH when GMP exists? |
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| GMP has "integers" (no digits after a decimal), "rational numbers" (stored as |
| 2 integers) and "floats". None of these will correctly represent a POSIX BC |
| number. Floats are the closest, but will not behave correctly for many |
| computations. For example, BC numbers have a "scale" that represent the number |
| of digits to represent after the decimal point. The multiplying two of these |
| numbers requires one to calculate an exact number of digits after the decimal |
| point regardless of the number of digits in the integer part. GMP floats have |
| a "fixed, but arbitrary" mantissa and so multiplying two floats will end up |
| dropping digits BC must calculate. |
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| ## Credits |
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| Phil Nelson (philnelson@acm.org) wrote bcmath library. |
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| ## License |
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| The bcmath library is released under the GNU Lesser General Public License v2.1. |
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