mirror of
https://github.com/lcn2/calc.git
synced 2025-08-16 01:03:29 +03:00
58 lines
1.8 KiB
Plaintext
58 lines
1.8 KiB
Plaintext
NAME
|
|
ln - logarithm function
|
|
|
|
SYNOPSIS
|
|
ln(x [,eps])
|
|
|
|
TYPES
|
|
x nonzero real or complex
|
|
eps nonzero real, defaults to epsilon()
|
|
|
|
return real or complex
|
|
|
|
DESCRIPTION
|
|
Approximate the natural logarithm function of x by a multiple of
|
|
epsilon, the error having absolute value less than 0.75 * eps.
|
|
If n is a positive integer, ln(x, 10^-n) will usually be correct
|
|
to the n-th decimal place.
|
|
|
|
EXAMPLE
|
|
; print ln(10, 1e-5), ln(10, 1e-10), ln(10, 1e-15), ln(10, 1e-20)
|
|
2.30259 2.302585093 2.302585092994046 2.30258509299404568402
|
|
|
|
; print ln(2+3i, 1e-5), ln(2+3i, 1e-10)
|
|
1.28247+0.98279i 1.2824746787+0.9827937232i
|
|
|
|
LIMITS
|
|
x != 0
|
|
eps > 0
|
|
|
|
LINK LIBRARY
|
|
NUMBER *qln(NUMBER *x, NUMBER *eps)
|
|
COMPLEX *c_ln(COMPLEX *x, NUMBER *eps)
|
|
|
|
SEE ALSO
|
|
exp, acosh, asinh, atanh, log
|
|
|
|
## Copyright (C) 1999,2021 Landon Curt Noll
|
|
##
|
|
## Calc is open software; you can redistribute it and/or modify it under
|
|
## the terms of the version 2.1 of the GNU Lesser General Public License
|
|
## as published by the Free Software Foundation.
|
|
##
|
|
## Calc is distributed in the hope that it will be useful, but WITHOUT
|
|
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
|
|
## Public License for more details.
|
|
##
|
|
## A copy of version 2.1 of the GNU Lesser General Public License is
|
|
## distributed with calc under the filename COPYING-LGPL. You should have
|
|
## received a copy with calc; if not, write to Free Software Foundation, Inc.
|
|
## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
##
|
|
## Under source code control: 1995/10/11 04:41:26
|
|
## File existed as early as: 1995
|
|
##
|
|
## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
|
|
## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
|