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