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- BCMATH FAQ:
- 1) Why BCMATH?
- 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.
- 2) Why BCMATH when GMP exists?
- 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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