spm_fp_display_nullclines.m
8a186cd82567master

spm_fp_display_nullclines.m
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			function f = spm_fp_display_nullclines(M,x)
			% Nullcline plot of flow and sample trajectory
			% FORMAT spm_fp_display_nullclines(M,x)
			%
			% M - model specifying flow; M(1).f;
			% x - cell array of domain or support
			%
			% f - derivative of x(2)
			%__________________________________________________________________________
			% Copyright (C) 2005 Wellcome Trust Centre for Neuroimaging

			% Karl Friston
			% $Id: spm_fp_display_nullclines.m 2494 2008-11-26 20:08:15Z karl $

			% evaluation points and equilibria
			%--------------------------------------------------------------------------
			for i = 1:length(x)
			nx(i) = length(x{i});
			end
			X = spm_ndgrid(x);

			% flow fields
			%--------------------------------------------------------------------------
			for i = 1:size(X,1)
			try
			f(i,:) = feval(M(1).f,X(i,:)',0,M(1).pE)';
			catch
			f(i,:) = feval(M(1).f,X(i,:)',0,[],M(1).pE)';
			end
			end

			% exemplar trajectory; from M(1).x
			%--------------------------------------------------------------------------
			U.u = sparse(512,M(1).m);
			t = spm_int_J(M(1).pE,M,U);
			t = [M(1).x(:)'; t];

			% trajectory and nullclines
			%--------------------------------------------------------------------------
			f = reshape(f(:,2),nx(1),nx(2));
			image(x{1},x{2},64 - (f > 0)'*8), hold on
			plot(x{1},0*x{1},'k',t(:,1),t(:,2),'r',t(1,1),t(1,2),'or'), hold off
			axis square xy
			drawnow