1<?xml version="1.0" encoding="UTF-8"?> 2 3<!--*********************************************************** 4 * 5 * Licensed to the Apache Software Foundation (ASF) under one 6 * or more contributor license agreements. See the NOTICE file 7 * distributed with this work for additional information 8 * regarding copyright ownership. The ASF licenses this file 9 * to you under the Apache License, Version 2.0 (the 10 * "License"); you may not use this file except in compliance 11 * with the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, 16 * software distributed under the License is distributed on an 17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 18 * KIND, either express or implied. See the License for the 19 * specific language governing permissions and limitations 20 * under the License. 21 * 22 ***********************************************************--> 23 24<helpdocument version="1.0"> 25<meta> 26<topic id="textsbasicshared03080202xml" indexer="include" status="PUBLISH"> 27<title id="tit" xml-lang="en-US">Log Function [Runtime]</title> 28<filename>/text/sbasic/shared/03080202.xhp</filename> 29</topic> 30</meta> 31<body> 32<section id="log"> 33<bookmark xml-lang="en-US" branch="index" id="bm_id3149416"><bookmark_value>Log function</bookmark_value> 34</bookmark> 35<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> 36<paragraph role="paragraph" id="par_id3145066" xml-lang="en-US" l10n="U" oldref="2">Returns the natural logarithm of a number.</paragraph> 37</section> 38<paragraph role="heading" id="hd_id3159414" xml-lang="en-US" level="2" l10n="U" oldref="3">Syntax:</paragraph> 39<paragraph role="paragraph" id="par_id3154760" xml-lang="en-US" l10n="U" oldref="4">Log (Number)</paragraph> 40<paragraph role="heading" id="hd_id3149457" xml-lang="en-US" level="2" l10n="U" oldref="5">Return value:</paragraph> 41<paragraph role="paragraph" id="par_id3150791" xml-lang="en-US" l10n="U" oldref="6">Double</paragraph> 42<paragraph role="heading" id="hd_id3151211" xml-lang="en-US" level="2" l10n="U" oldref="7">Parameters:</paragraph> 43<paragraph role="paragraph" id="par_id3151041" xml-lang="en-US" l10n="U" oldref="8"> 44<emph>Number:</emph> Any numeric expression that you want to calculate the natural logarithm for.</paragraph> 45<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> 46<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> 47<paragraph role="paragraph" id="par_id3145420" xml-lang="en-US" l10n="U" oldref="11">Log n(x) = Log(x) / Log(n)</paragraph> 48<embed href="text/sbasic/shared/00000003.xhp#errorcode"/> 49<embed href="text/sbasic/shared/00000003.xhp#err5"/> 50<paragraph role="heading" id="hd_id3155131" xml-lang="en-US" level="2" l10n="U" oldref="12">Example:</paragraph> 51<paragraph role="paragraph" id="par_id3152463" xml-lang="en-US" l10n="U" oldref="13">Sub ExampleLogExp</paragraph> 52<paragraph role="paragraph" id="par_id3145750" xml-lang="en-US" l10n="U" oldref="14">Dim a as Double</paragraph> 53<paragraph role="paragraph" id="par_id3151116" xml-lang="en-US" l10n="U" oldref="15">Dim const b1=12.345e12</paragraph> 54<paragraph role="paragraph" id="par_id3146985" xml-lang="en-US" l10n="U" oldref="16">Dim const b2=1.345e34</paragraph> 55<paragraph role="paragraph" id="par_id3148616" xml-lang="en-US" l10n="U" oldref="17">a=Exp( Log(b1)+Log(b2) )</paragraph> 56<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> 57<paragraph role="paragraph" id="par_id3155411" xml-lang="en-US" l10n="U" oldref="19">end sub</paragraph> 58</body> 59</helpdocument> 60