<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD> <TITLE>void FIRlowpass_double_filter</TITLE> <META NAME="GENERATOR" CONTENT="DOC++ 3.4.6"> </HEAD> <body bgcolor="#ffffff" link="#0000ff" vlink="#dd0000" text="#000088" alink="9000ff"> <A HREF = "http://www.cstr.ed.ac.uk/"> <IMG align=left BORDER=0 SRC = "cstr.gif"></A> <A HREF="http://www.cstr.ed.ac.uk/projects/speech_tools.html"> <IMG BORDER=0 ALIGN=right SRC="est.jpg" width=150 height=93></A> <br> <br clear=left> <p align=right> In file ../include/sigpr/EST_filter.h:<TABLE BORDER=0><TR> <TD VALIGN=TOP><H2>void <A HREF="#DOC.DOCU">FIRlowpass_double_filter</A></H2></TD><TD><H2>(<!1><A HREF="EST_Wave.html">EST_Wave</A> &sigin, int <!1><A HREF="EST_String.html#DOC.75.48.1">freq</A>,<BR> int order=DEFAULT_FILTER_ORDER)</H2></TD></TR></TABLE> <BLOCKQUOTE>Quick function for one-off zero phase high pass filtering.</BLOCKQUOTE> <A NAME="DOC.DOCU"></A> <HR> <H2>Documentation</H2> <BLOCKQUOTE>Quick function for one-off zero phase high pass filtering. <P>Normal high pass filtering (<!1><A HREF="FIRhighpass_filter.html">FIRhighpass_filter</A>) introduces a time delay. This function filters the signal twice, first forward and then backwards, which ensures a zero phase lag. Hence the order parameter need only be half what it is for (<!1><A HREF="FIRhighpass_filter.html">FIRhighpass_filter</A> to achieve the same effect. <P></BLOCKQUOTE> <DL><DT><DT><B>Parameters:</B><DD><B>in_sig</B> - input waveform, which will be overwritten <BR><B></B> - <!1><A HREF="EST_String.html#DOC.75.48.1">freq</A> cutoff <!1><A HREF="EST_DiscreteProbDistribution.html#DOC.85.18">frequency</A> in Hertz <BR><B>order</B> - number of filter coefficients, eg. 99 <BR><DT><B>See Also:</B><DD><!1><A HREF="FIRlowpass_filter.html">FIRlowpass_filter</A><BR><DD></DL><P><P><I><A HREF="index.html">Alphabetic index</A></I> <I><A HREF="HIER.html">HTML hierarchy of classes</A> or <A HREF="HIERjava.html">Java</A></I></P><HR> <A HREF = "http://www.ed.ac.uk/"> <IMG align=right BORDER=0 SRC = "edcrest.gif"></A> <P Align=left><I>This page is part of the <A HREF="http://www.cstr.ed.ac.uk/projects/speech_tools.html"> Edinburgh Speech Tools Library</A> documentation <br> Copyright <A HREF="http://www.ed.ac.uk"> University of Edinburgh</A> 1997 <br> Contact: <A HREF="mailto:speech_toolss@cstr.ed.ac.uk"> speech_tools@cstr.ed.ac.uk </a> </P> <br clear=right>