1<?xml version="1.0" encoding="UTF-8"?> 2 3 4<!--*********************************************************************** 5 * 6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 7 * 8 * Copyright 2000, 2010 Oracle and/or its affiliates. 9 * 10 * OpenOffice.org - a multi-platform office productivity suite 11 * 12 * This file is part of OpenOffice.org. 13 * 14 * OpenOffice.org is free software: you can redistribute it and/or modify 15 * it under the terms of the GNU Lesser General Public License version 3 16 * only, as published by the Free Software Foundation. 17 * 18 * OpenOffice.org is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 * GNU Lesser General Public License version 3 for more details 22 * (a copy is included in the LICENSE file that accompanied this code). 23 * 24 * You should have received a copy of the GNU Lesser General Public License 25 * version 3 along with OpenOffice.org. If not, see 26 * <http://www.openoffice.org/license.html> 27 * for a copy of the LGPLv3 License. 28 * 29 ************************************************************************--> 30 31<helpdocument version="1.0"> 32<meta> 33<topic id="textsbasicshared03080202xml" indexer="include" status="PUBLISH"> 34<title id="tit" xml-lang="en-US">Log Function [Runtime]</title> 35<filename>/text/sbasic/shared/03080202.xhp</filename> 36</topic> 37<history> 38<created date="2003-10-31T00:00:00">Sun Microsystems, Inc.</created> 39<lastedited date="2004-08-24T13:28:25">converted from old format - fpe</lastedited> 40</history> 41</meta> 42<body> 43<section id="log"> 44<bookmark xml-lang="en-US" branch="index" id="bm_id3149416"><bookmark_value>Log function</bookmark_value> 45</bookmark> 46<paragraph role="heading" id="hd_id3149416" xml-lang="en-US" level="1" l10n="U" oldref="1"><link href="text/sbasic/shared/03080202.xhp" name="Log Function [Runtime]">Log Function [Runtime]</link></paragraph> 47<paragraph role="paragraph" id="par_id3145066" xml-lang="en-US" l10n="U" oldref="2">Returns the natural logarithm of a number.</paragraph> 48</section> 49<paragraph role="heading" id="hd_id3159414" xml-lang="en-US" level="2" l10n="U" oldref="3">Syntax:</paragraph> 50<paragraph role="paragraph" id="par_id3154760" xml-lang="en-US" l10n="U" oldref="4">Log (Number)</paragraph> 51<paragraph role="heading" id="hd_id3149457" xml-lang="en-US" level="2" l10n="U" oldref="5">Return value:</paragraph> 52<paragraph role="paragraph" id="par_id3150791" xml-lang="en-US" l10n="U" oldref="6">Double</paragraph> 53<paragraph role="heading" id="hd_id3151211" xml-lang="en-US" level="2" l10n="U" oldref="7">Parameters:</paragraph> 54<paragraph role="paragraph" id="par_id3151041" xml-lang="en-US" l10n="U" oldref="8"> 55<emph>Number:</emph> Any numeric expression that you want to calculate the natural logarithm for.</paragraph> 56<paragraph role="paragraph" id="par_id3150869" xml-lang="en-US" l10n="U" oldref="9">The natural logarithm is the logarithm to the base e. Base e is a constant with an approximate value of 2.718282...</paragraph> 57<paragraph role="paragraph" id="par_id3153968" xml-lang="en-US" l10n="U" oldref="10">You can calculate logarithms to any base (n) for any number (x) by dividing the natural logarithm of x by the natural logarithm of n, as follows:</paragraph> 58<paragraph role="paragraph" id="par_id3145420" xml-lang="en-US" l10n="U" oldref="11">Log n(x) = Log(x) / Log(n)</paragraph> 59<embed href="text/sbasic/shared/00000003.xhp#errorcode"/> 60<embed href="text/sbasic/shared/00000003.xhp#err5"/> 61<paragraph role="heading" id="hd_id3155131" xml-lang="en-US" level="2" l10n="U" oldref="12">Example:</paragraph> 62<paragraph role="paragraph" id="par_id3152463" xml-lang="en-US" l10n="U" oldref="13">Sub ExampleLogExp</paragraph> 63<paragraph role="paragraph" id="par_id3145750" xml-lang="en-US" l10n="U" oldref="14">Dim a as Double</paragraph> 64<paragraph role="paragraph" id="par_id3151116" xml-lang="en-US" l10n="U" oldref="15">Dim const b1=12.345e12</paragraph> 65<paragraph role="paragraph" id="par_id3146985" xml-lang="en-US" l10n="U" oldref="16">Dim const b2=1.345e34</paragraph> 66<paragraph role="paragraph" id="par_id3148616" xml-lang="en-US" l10n="U" oldref="17">a=Exp( Log(b1)+Log(b2) )</paragraph> 67<paragraph role="paragraph" id="par_id3149262" xml-lang="en-US" l10n="U" oldref="18">MsgBox "" & a & chr(13) & (b1*b2) ,0,"Multiplication by logarithm function"</paragraph> 68<paragraph role="paragraph" id="par_id3155411" xml-lang="en-US" l10n="U" oldref="19">end sub</paragraph> 69</body> 70</helpdocument> 71