function spm_fMRI_design_show(SPM,s,i)
% Interactive review of fMRI design matrix
% FORMAT spm_fMRI_design_show(SPM,s,i)
%
% Sess(s).U(i)  -  see spm_fMRI_design for session s, trial i.
%
%_______________________________________________________________________
% Copyright (C) 2008 Wellcome Trust Centre for Neuroimaging

% Karl Friston
% $Id: spm_fMRI_design_show.m 4469 2011-09-08 10:58:07Z guillaume $


% SPM
%-----------------------------------------------------------------------
if nargin == 0
    load(spm_select(1,'^SPM\.mat$','Select SPM.mat'));
end

Sess  = SPM.Sess;

% Do not proceed unless there are trials specified
%-----------------------------------------------------------------------
for j = 1:length(Sess)
    if ~length(Sess(j).U)
        spm('alert*','User-specifed regressors only!',mfilename,sqrt(-1));
        return
    end
end

%-Defaults: Setup GUI if not called by spm_DesRep (with s and i)
%-----------------------------------------------------------------------
if nargin < 3
    s = 1;
    i = 1;

    %-Get Interactive window and delete any previous DesRepUI menu
    %---------------------------------------------------------------
    Finter = spm_figure('GetWin','Interactive');
    delete(findobj(get(Finter,'Children'),'flat','Tag','DesRepUI'))

    %-Create menu
    %---------------------------------------------------------------
    hC     = uimenu(Finter,'Label','Explore fMRI design',...
        'Separator','on',...
        'Tag','DesRepUI',...
        'UserData',SPM,...
        'HandleVisibility','on');
    for j = 1:length(Sess)
        h     = uimenu(hC,'Label',sprintf('Session %.0f ',j),...
            'HandleVisibility','off');
        for k = 1:length(Sess(j).Fc)
            cb = ['tmp = get(get(gcbo,''UserData''),',...
                             '''UserData''); ',...
                sprintf(['spm_fMRI_design_show(',...
                    'tmp,%d,%d);'],j,k)];
            uimenu(h,'Label',Sess(j).Fc(k).name,...
                         'CallBack',cb,...
                         'UserData',hC,...
                         'HandleVisibility','off')
        end
    end
end


%-Graphics...
%=======================================================================

%-Get Graphics window
%-----------------------------------------------------------------------
Fgraph = spm_figure('GetWin','Graphics');
spm_results_ui('Clear',Fgraph,0)


% Trial-specific regressors - time domain
%-----------------------------------------------------------------------
sX    = SPM.xX.X(Sess(s).row,Sess(s).col);
rX    = sX(:,Sess(s).Fc(i).i);
subplot(2,2,1)
plot(Sess(s).row,rX)
xlabel('scan')
ylabel('regressor[s]')
title({'Time domain',['regressors for ' Sess(s).Fc(i).name]})
grid on
axis tight

% Trial-specific regressors - frequency domain
%-----------------------------------------------------------------------
subplot(2,2,2)
gX    = abs(fft(rX)).^2;
gX    = gX*diag(1./sum(gX));
q     = size(gX,1);
Hz    = [0:(q - 1)]/(q*SPM.xY.RT);
q     = 2:fix(q/2);
plot(Hz(q),gX(q,:))
HPF = SPM.xX.K(s).HParam;
patch([0 1 1 0]/HPF,[0 0 1 1]*max(max(gX)),[1 1 1]*.9,'facealpha',.5);
xlabel('Frequency (Hz)')
ylabel('relative spectral density')
h=title(['Frequency domain',sprintf('\n'), ' {\bf',num2str(HPF),'}', ...
    ' second High-pass filter'],'Interpreter','Tex');
grid on
axis tight

% if trial (as opposed to trial x trial interaction)
%-----------------------------------------------------------------------
if length(Sess(s).U) >= i

    % Basis set and peristimulus sampling
    %---------------------------------------------------------------
    subplot(2,2,3)
    dt   = Sess(s).U(i).dt;
    RT   = SPM.xY.RT;
    t    = [1:size(SPM.xBF.bf,1)]*dt;
    pst  = Sess(s).U(i).pst;
    plot(t,SPM.xBF.bf,pst,0*pst,'.','MarkerSize',16)
    str  = sprintf('TR = %0.2fsecs',RT);
    xlabel({'time (secs)' str sprintf('%0.0fms time bins',1000*dt)})
    title({'Basis set and peristimulus sampling' SPM.xBF.name})
    axis tight
    grid on

    % if a paramteric variate is specified
    %---------------------------------------------------------------
    for p = 1:length(Sess(s).U(i).P)

        if Sess(s).U(i).P(p).h

        % onsets and parametric modulation
        %-------------------------------------------------------
        subplot(2,2,4)
        ons = Sess(s).U(i).ons;
        plot(ons,Sess(s).U(i).P(p).P,'.','MarkerSize',8)
        xlabel('time {secs}')
        title('parameters')
        grid on
        hold on

        end
    end
end

%-Pop up Graphics figure window
%-----------------------------------------------------------------------
figure(Fgraph);