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18 lines
829 B
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18 lines
829 B
Plaintext
Because of frequent questions ....... here is the BC FAQ
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1) Why does BC have its own arbitrary precision number routines
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(found in lib/number.c) rather than using GMP?
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GMP has "integers" (no digits after a decimal), "rational numbers"
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(stored as 2 integers) and "floats". None of these will correctly
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represent a POSIX BC number. Floats are the closest, but will not
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behave correctly for many computations. For example, BC numbers have
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a "scale" that represent the number of digits to represent after the
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decimal point. The multiplying two of these numbers requires one to
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calculate an exact number of digits after the decimal point regardless
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of the number of digits in the integer part. GMP floats have a
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"fixed, but arbitrary" mantissa and so multiplying two floats will end
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up dropping digits BC must calculate.
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