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4e75fbab49
Adding test-library option to automatically infer tests from libraries. Processing scribble docs even when we can't load the module.
16 lines
706 B
Scheme
16 lines
706 B
Scheme
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;;> Library for computing (optionally continuously) compounded interest.
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(define-library (euler interest)
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(export compound-interest)
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(import (scheme base) (scheme inexact))
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(begin
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;;> Returns the total amount starting at \var{base} increasing at
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;;> the given interest rate \var{rate}, for the given \var{duration}.
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;;> Compounds at optional \var{interval} intervals, which default
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;;> to +inf.0 for continuous.
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(define (compound-interest base rate duration . o)
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(let ((interval (or (and (pair? o) (car o)) +inf.0)))
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(if (finite? interval)
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(* base (expt (+ 1 (/ rate interval)) (* duration interval)))
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(* base (exp (* rate duration))))))))
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