function filt(h,ts,colinds,T)
%FEVAL
%
% Author(s): James G. Owen
% Revised:
% Copyright 1986-2003 The MathWorks, Inc.
% $Revision: 1.1.6.1 $ $Date: 2004/12/26 21:39:38 $

%% Initialize recorder
recorder = tsguis.recorder;

%% No-op for vacuous time series
if ts.TimeInfo.length<2
    return
end

%% Detrending
if strcmp(h.Detrendactive,'on')
    ts.detrend(h.Detrendtype,colinds);
    if strcmp(recorder.Recording,'on')
        T.addbuffer('%% Detrending time series');
        T.addbuffer(['detrend(' ts.Name, ',''' h.Detrendtype ...
               ''',[' num2str(colinds), ']);'],ts);
    end        
end

%% Filtering
if strcmp(h.Filteractive,'on') 
    % TO DO: What if the first or last point contains a NaN?
    % Discrte transfer fcn
    if strcmp(h.Filter,'transfer')
        ts.filter(h.Bcoeffs,h.Acoeffs,colinds);
        if strcmp(recorder.Recording,'on')
            T.addbuffer('%% Filtering time series');
            T.addbuffer(['filter(' ts.Name ',[' num2str(h.Bcoeffs) '],[' ...
                 num2str(h.Acoeffs) '],[' num2str(colinds) ']);'],ts);
        end
    % Ideal continuous
    elseif strcmp(h.Filter,'ideal')
        unitfactor = tsunitconv(ts.TimeInfo.Units,h.ViewNode.Plot.TimeUnits);
        ts.idealfilter(unitfactor*h.range,h.Band,colinds);
        if strcmp(recorder.Recording,'on')
            T.addbuffer('%% Filtering time series');
            T.addbuffer(['idealfilter(' ts.Name ',[' ...
                    num2str(h.Range*unitfactor) '],''' h.Band ''',[' num2str(colinds) ']);'],ts);
        end 
    % First order
    elseif strcmp(h.Filter,'firstord')
        unitfactor = tsunitconv(ts.TimeInfo.Units,h.ViewNode.Plot.TimeUnits);
        % Non-uniformly sampled
        if isnan(ts.TimeInfo.Increment)
               Ts = (ts.TimeInfo.End-ts.TimeInfo.Start)/ts.TimeInfo.length;
               ts.resample(linspace(ts.TimeInfo.Start,ts.TimeInfo.End,ts.TimeInfo.length));
               ts.filter(Ts/(h.Timeconst*unitfactor+Ts),...
                   [1 -h.Timeconst*unitfactor/(h.Timeconst*unitfactor+Ts)],colinds);
               if strcmp(recorder.Recording,'on')
                   T.addbuffer(['Ts = (' ts.Name '.TimeInfo.End-' ts.Name '.TimeInfo.Start)/' ...
                       ts.Name '.TimeInfo.length;'],ts);
                   T.addbuffer(['resample(' ts.Name ',linspace(' ts.Name '.TimeInfo.Start,' ...
                       ts.Name '.TimeInfo.End,' ts.Name '.TimeInfo.length));']);
                   T.addbuffer(['filter(' ts.Name ',Ts/('  num2str(h.Timeconst*unitfactor) '+Ts),[1 -' ...
                       num2str(h.Timeconst*unitfactor) '/(' num2str(h.TimeConst*unitfactor) '+Ts)],[' ...
                       num2str(colinds) ']);']);
               end   
        % Uniformly sampled
        else 
            try
                ts.filter(ts.TimeInfo.Increment/(h.Timeconst*unitfactor+ts.TimeInfo.Increment),...
                   [1 -h.Timeconst*unitfactor/(h.Timeconst*unitfactor+ts.TimeInfo.Increment)],colinds);
            catch
                err1 = lasterror;
                if strcmp(err1.identifier,'timeseries:filter:allnans')  
                    msg = 'Filtering operation failed because one of the selected time series contains NaN(s) at the beggining or end.';
                else
                    msg = ['Filtering operation failed. Error from filter methods was ' err1.message];
                end
                errordlg(msg,'Time Series Tool','modal')
                return
            end
            if strcmp(recorder.Recording,'on')
                T.addbuffer(['filter(' ts.Name ',' ts.Name ...
                    '.TimeInfo.Increment/(' num2str(h.Timeconst*unitfactor) ...
                    '+' ts.Name '.TimeInfo.Increment),[1 -' num2str(h.Timeconst*unitfactor) ...
                    '/(' num2str(h.Timeconst*unitfactor) ...
                    '+' ts.Name '.TimeInfo.Increment)],[' num2str(colinds) ']);'],ts);
            end
        end
    end
end