nt_peaksign

sgn=peaksign(x,dim) - sign of largest extremum
 
 If dim is present, give array of signs along that dimension

0001 function sgn=nt_peaksign(x,dim)
0002 %sgn=peaksign(x,dim) - sign of largest extremum
0003 %
0004 % If dim is present, give array of signs along that dimension
0005 
0006 if nargin<2; dim=[]; end
0007 
0008 if isempty(dim)
0009     if max(-x(:))>max(x(:));
0010         sgn=-1;
0011     else
0012         sgn=1;
0013     end
0014 else
0015     if dim>4; error('1'); end
0016     [m,n,o,p]=size(x);
0017     if dim==1
0018         for k=1:m
0019             sgn(k)=nt_peaksign(x(k,:,:,:));
0020         end
0021     elseif dim==2
0022         for k=1:n
0023             sgn(k)=nt_peaksign(x(:,k,:,:));
0024         end
0025     elseif dim==3
0026         for k=1:o
0027             sgn(k)=nt_peaksign(x(:,:,k,:));
0028         end
0029     else
0030         for k=1:p
0031             sgn(k)=nt_peaksign(x(:,:,:,k));
0032         end
0033     end
0034 end
0035