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65 lines
1.9 KiB
Plaintext
65 lines
1.9 KiB
Plaintext
NAME
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log - base 10 logarithm
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SYNOPSIS
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log(x [,eps])
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TYPES
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x 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 10 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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If n is a positive integer, log(x, 10^-n) will usually be correct
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to the n-th decimal place.
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EXAMPLE
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; print log(10), log(100), log(1e10), log(1e500)
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1 2 10 500
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; print log(128), log(23209), log(2^17-19)
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~2.10720996964786836649 ~4.36565642852838930424 ~5.11744696704937330414
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; print log(2+3i, 1e-5)
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~0.55696845725899964822+~0.42681936428109216144i
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LIMITS
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x != 0
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eps > 0
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LINK LIBRARY
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NUMBER *qlog(NUMBER *x, NUMBER *eps)
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COMPLEX *c_log(COMPLEX *x, NUMBER *eps)
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SEE ALSO
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ln
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## Copyright (C) 2006 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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## 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
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##
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## @(#) $Revision: 29.1 $
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## @(#) $Id: log,v 29.1 2006/05/07 12:59:00 chongo Exp $
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## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/log,v $
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##
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## Under source code control: 2006/05/06 23:56:04
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## File existed as early as: 2006
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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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