function [dS,t,f]=mtdspecgrampb(data,movingwin,phi,params)
% Multi-taper derivatives of time-frequency spectrum - binned point process
%
% Usage:
%
% [dS,t,f]=mtdspecgrampb(data,movingwin,phi,params)
% Input:
% Note that all times can be in arbitrary units. But the units have to be
% consistent. So, if E is in secs, win, t have to be in secs, and Fs has to
% be Hz. If E is in samples, so are win and t, and Fs=1. In case of spike
% times, the units have to be consistent with the units of data as well.
% data (in form samples x channels/trials or a single vector) -- required
% movingwin (in the form [window winstep] i.e length of moving
% window and step size.
% Note that units here have
% to be consistent with
% units of Fs
% phi (angle for evaluation of derivative) -- required.
% e.g. phi=[0,pi/2] giving the time and frequency
% derivatives
% params: structure with fields tapers, pad, Fs, fpass,trialave
% -optional
% tapers : precalculated tapers from dpss or in the one of the following
% forms:
% (1) A numeric vector [TW K] where TW is the
% time-bandwidth product and K is the number of
% tapers to be used (less than or equal to
% 2TW-1).
% (2) A numeric vector [W T p] where W is the
% bandwidth, T is the duration of the data and p
% is an integer such that 2TW-p tapers are used. In
% this form there is no default i.e. to specify
% the bandwidth, you have to specify T and p as
% well. Note that the units of W and T have to be
% consistent: if W is in Hz, T must be in seconds
% and vice versa. Note that these units must also
% be consistent with the units of params.Fs: W can
% be in Hz if and only if params.Fs is in Hz.
% The default is to use form 1 with TW=3 and K=5
% Note that T has to be equal to movingwin(1).
%
% pad (padding factor for the FFT) - optional (can take values -1,0,1,2...).
% -1 corresponds to no padding, 0 corresponds to padding
% to the next highest power of 2 etc.
% e.g. For N = 500, if PAD = -1, we do not pad; if PAD = 0, we pad the FFT
% to 512 points, if pad=1, we pad to 1024 points etc.
% Defaults to 0.
% Fs (sampling frequency) - optional. Default 1.
% fpass (frequency band to be used in the calculation in the form
% [fmin fmax])- optional.
% Default all frequencies between 0 and
% Fs/2
% trialave (average over trials when 1, don't average when 0) -
% optional. Default 0
% Output:
% dS (spectral derivative in form phi x time x frequency x channels/trials if trialave=0;
% phi x time x frequency if trialave=1)
% t (times)
% f (frequencies)
if nargin < 3; error('Need data, window parameters and angle'); end;
if nargin < 4; params=[]; end;
if length(params.tapers)==3 & movingwin(1)~=params.tapers(2);
error('Duration of data in params.tapers is inconsistent with movingwin(1), modify params.tapers(2) to proceed')
end
[tapers,pad,Fs,fpass,err,trialave,params]=getparams(params);
clear err
data=change_row_to_column(data);
[N,Ch]=size(data);
Nwin=round(Fs*movingwin(1)); % number of samples in window
Nstep=round(movingwin(2)*Fs); % number of samples to step through
nfft=max(2^(nextpow2(Nwin)+pad),Nwin);
f=getfgrid(Fs,nfft,fpass); Nf=length(f);
params.tapers=dpsschk(tapers,Nwin,Fs); % check tapers
winstart=1:Nstep:N-Nwin+1;
nw=length(winstart);
if trialave==0; dS=zeros(length(phi),nw,Nf,Ch); else dS=zeros(length(phi),nw,Nf); end;
for n=1:nw;
indx=winstart(n):winstart(n)+Nwin-1;
datawin=data(indx,:);
[ds,f]=mtdspectrumpb(datawin,phi,params);
dS(:,n,:,:)=ds;
end;
sz=size(ds);
dS=squeeze(dS);
% if length(sz)==3;
% dS=permute(dS,[2 1 3 4]);
% elseif length(phi)>1
% dS=permute(dS,[2 1 3]);
% end;
winmid=winstart+round(Nwin/2);
t=winmid/Fs;