Index: trunk/src/transform_field/signal_lowpass_filter.m
===================================================================
--- trunk/src/transform_field/signal_lowpass_filter.m	(revision 1144)
+++ trunk/src/transform_field/signal_lowpass_filter.m	(revision 1144)
@@ -0,0 +1,50 @@
+% 'signal_low_pass_filter': low pass filter of input  signals
+
+% OUTPUT: 
+% DataOut: Matlab structure representing the output (filtered) field
+%
+%INPUT:
+% DataIn: Matlab structure representing the input field
+
+%=======================================================================
+% Copyright 2008-2024, LEGI UMR 5519 / CNRS UGA G-INP, Grenoble, France
+%   http://www.legi.grenoble-inp.fr
+%   Joel.Sommeria - Joel.Sommeria (A) univ-grenoble-alpes.fr
+%
+%     This file is part of the toolbox UVMAT.
+%
+%     UVMAT is free software; you can redistribute it and/or modify
+%     it under the terms of the GNU General Public License as published
+%     by the Free Software Foundation; either version 2 of the license,
+%     or (at your option) any later version.
+%
+%     UVMAT is distributed in the hope that it will be useful,
+%     but WITHOUT ANY WARRANTY; without even the implied warranty of
+%     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+%     GNU General Public License (see LICENSE.txt) for more details.
+%=======================================================================
+
+function DataOut=signal_bandpass_filter(DataIn,Param)
+
+%% request input parameters
+if isfield(DataIn,'Action') && isfield(DataIn.Action,'RUN') && isequal(DataIn.Action.RUN,0)
+        [DataOut.TransformInput,errormsg] = set_param_input({'WindowLength'},{11},Param)  
+    return
+end
+DataOut=DataIn; 
+WindowLength=Param.TransformInput.WindowLength;
+HalfLength=floor(WindowLength/2);
+WindowLength=2*HalfLength+1;
+WindowLength=2*ceil(WindowLength/2);%set to the closes upper value
+B=ones(1,WindowLength)/WindowLength;
+for ivar=2:numel(DataIn.ListVarName)
+    VarName=DataIn.ListVarName{ivar};
+    DataOut.(VarName)=filter(B,1,DataIn.(VarName));%teke the sliding average on WindowLength values
+end
+CoordName=DataIn.ListVarName{1};
+FirstX=DataIn.(CoordName)(1);
+DataOut.(CoordName)=circshift(DataIn.(CoordName),HalfLength);% shift the x coordinate to compensate phase shift produced by the filter
+DataOut.(CoordName)(1:HalfLength)=FirstX;
+
+
+