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5a117d542a
NOTE: The `log2(x [,eps])` and `logn(x, n [,eps])` builtin functions are NOT yet implemented.
69 lines
2.1 KiB
Plaintext
69 lines
2.1 KiB
Plaintext
NAME
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logn - base n logarithm
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SYNOPSIS
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logn(x, n [,eps])
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TYPES
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x nonzero real or complex
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n nonzero real or complex
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eps nonzero real, defaults to epsilon()
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return real or complex
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DESCRIPTION
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Approximate the base n logarithm function of x by a multiple of
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epsilon, the error having absolute value less than 0.75 * eps.
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The base, n, must not be 0 nor 1.
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If y is a positive integer, log(x, n^-y) will usually be correct
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to the y-th decimal place.
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EXAMPLE
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; print logn(15.625, 2.5), logn(15.625, 2.5, 1e-25)
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~ 3.00000000000000000001 3
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; print logn(127, 1/13), log(23209, sqrt(3)), logn(2^17-19, 17)
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~ -1.88860925162778125111 6 ~ 4.15900804831225415076
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; print logn(-1, 1i), logn(2+3i, 3i+2), logn(2+3i, 3i)
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2 1 ~ 0.80360095345990217753 - ~ 0.25441159318835790311i
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; print logn(22+3i, 3i, 1e-50)
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~ 0.98489914201047045408 - ~ 1.28484657882287682702i
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LIMITS
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x != 0
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n != 0 && n != 1
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eps > 0
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LINK LIBRARY
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NUMBER *qlogn(NUMBER *x, NUMBER *n, NUMBER *eps)
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COMPLEX *c_logn(COMPLEX *x, COMPLEX *n, NUMBER *eps)
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SEE ALSO
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ilog, ilogn, ilog10, ilog2, ln, log, log2
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## Copyright (C) 2023 Landon Curt Noll
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##
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## Calc is open software; you can redistribute it and/or modify it under
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## the terms of the version 2.1 of the GNU Lesser General Public License
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## as published by the Free Software Foundation.
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##
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## Calc is distributed in the hope that it will be useful, but WITHOUT
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## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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## Public License for more details.
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##
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## A copy of version 2.1 of the GNU Lesser General Public License is
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## distributed with calc under the filename COPYING-LGPL. You should have
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## received a copy with calc; if not, write to Free Software Foundation, Inc.
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## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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##
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## Under source code control: 2023/08/19 09:14:04
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## File existed as early as: 2023
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##
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## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
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## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
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