source: issm/trunk/src/m/miscellaneous/prctile_issm.m@ 23189

%
%  wrapper for prctile to avoid using the matlab statistics toolbox.
%
function [y]=prctile_issm(x,p,dim)

        try
                y=prctile(argin{:});

        catch me
                if length(size(x)) > 2
                        error('Number of dimensions %d not implemented.',length(size(x)));
                end
                if ~exist('dim','var')
                        dim=0;
                        for i=1:length(size(x))
                                if ~dim && size(x,i)>1
                                        dim=i;
                                end
                        end
                        if ~dim
                                dim=1;
                        end
                end

                psize=size(p);
                if size(p,2)>1
                        p=transpose(p);
                end

                xsize=size(x);
                if dim==2
                        x=transpose(x);
                end

%  check for any NaN in any columns

                if ~any(any((isnan(x))))
                        x=sort(x,1);
                        n=size(x,1);

%  branch based on number of elements

                        if     n>1

%  set up percent values and interpolate

                                xi=transpose(100.*([1:n]-0.5)/n);
                                y=interp1q(xi,x,p);

%  fill in high and low values
                                y(p<xi(1),:)=repmat(x(1,:),nnz(p<xi(1)),1);
                                y(p>xi(n),:)=repmat(x(n,:),nnz(p>xi(n)),1);

%  if one value, just copy it

                        elseif n==1
                                y=repmat(x(1,:),length(p),1);

%  if no values, use NaN

                        else
                                y=repmat(NaN,size(p,1),size(x,2));
                        end

                else

%  must loop over columns, since number of elements could be different

                        y=zeros(size(p,1),size(x,2));
                        for j=1:size(x,2)

%  remove any NaN and recursively call column

                                y(:,j)=prctile_issm(x(~isnan(x(:,j)),j),p);
                        end
                end

                if (min(xsize)==1 && xsize(dim)>1 && psize(2)>1) || ...
                   (min(xsize)> 1 && dim==2)
                        y=transpose(y);
                end
        end
end