<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE erlref SYSTEM "erlref.dtd"> <erlref> <header> <copyright> <year>1996</year> <year>2016</year> <holder>Ericsson AB, All Rights Reserved</holder> </copyright> <legalnotice> Licensed 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. The Initial Developer of the Original Code is Ericsson AB. </legalnotice> <title>math</title> <prepared>Joe Armstrong</prepared> <responsible>Bjarne Däcker</responsible> <docno>1</docno> <approved>Bjarne Däcker</approved> <checked></checked> <date>1997-01-15</date> <rev>B</rev> <file>math.xml</file> </header> <module since="">math</module> <modulesummary>Mathematical functions.</modulesummary> <description> <p>This module provides an interface to a number of mathematical functions.</p> <note> <p>Not all functions are provided on all platforms. In particular, the <seealso marker="#erf/1"><c>erf/1</c></seealso> and <seealso marker="#erfc/1"><c>erfc/1</c></seealso> functions are not provided on Windows.</p> </note> </description> <funcs> <func> <name name="acos" arity="1" since=""/> <name name="acosh" arity="1" since=""/> <name name="asin" arity="1" since=""/> <name name="asinh" arity="1" since=""/> <name name="atan" arity="1" since=""/> <name name="atan2" arity="2" since=""/> <name name="atanh" arity="1" since=""/> <name name="ceil" arity="1" since="OTP 20.0"/> <name name="cos" arity="1" since=""/> <name name="cosh" arity="1" since=""/> <name name="exp" arity="1" since=""/> <name name="floor" arity="1" since="OTP 20.0"/> <name name="fmod" arity="2" since="OTP 20.0"/> <name name="log" arity="1" since=""/> <name name="log10" arity="1" since=""/> <name name="log2" arity="1" since="OTP 18.0"/> <name name="pow" arity="2" since=""/> <name name="sin" arity="1" since=""/> <name name="sinh" arity="1" since=""/> <name name="sqrt" arity="1" since=""/> <name name="tan" arity="1" since=""/> <name name="tanh" arity="1" since=""/> <fsummary>Diverse math functions.</fsummary> <type variable="X" name_i="6"/> <type variable="Y" name_i="6"/> <desc> <p>A collection of mathematical functions that return floats. Arguments are numbers.</p> </desc> </func> <func> <name name="erf" arity="1" since=""/> <fsummary>Error function.</fsummary> <desc> <p>Returns the error function of <c><anno>X</anno></c>, where:</p> <pre> erf(X) = 2/sqrt(pi)*integral from 0 to X of exp(-t*t) dt.</pre> </desc> </func> <func> <name name="erfc" arity="1" since=""/> <fsummary>Another error function.</fsummary> <desc> <p><c>erfc(X)</c> returns <c>1.0</c> - <c>erf(X)</c>, computed by methods that avoid cancellation for large <c><anno>X</anno></c>.</p> </desc> </func> <func> <name name="pi" arity="0" since=""/> <fsummary>A useful number.</fsummary> <desc> <p>A useful number.</p> </desc> </func> </funcs> <section> <title>Limitations</title> <p>As these are the C library, the same limitations apply.</p> </section> </erlref>