function redo_minmax(nc)
% redo_minmax: recomputes the mins and maxs of non-coordinate variables
%
% usage: redo_minmax(nc);
%   where nc is a netcdf object that was already opened by
%   nc=netcdf('file_name.cdf','write')
% autonan MUST be ON before the .nc file is loaded for gmin and gmax to
% work correctly on 1e35, since gmin and gmax actually look for NaN
% from MM code in sg2nc.m
% emontgomery@usgs.gov


if ~(nargin ==1); help (mfilename); return
end

if ~exist('nctbx_options','var'),
    global nctbx_options;
    nctbx = 0;
else
    nctbx = 1;
end

theVars = var(nc);
if ~autonan(theVars{1}),
    % close and open the file to set autonan
    theFileName = char(ncnames(nc));
    close(nc)
    nctbx_options.theAutoNaN = 1;
    nc = netcdf(theFileName,'write');
end

theVars = var(nc);
for i = 1:length(theVars),
    if (~strcmp(ncnames(theVars{i}),'time') && ~strcmp(ncnames(theVars{i}),'time2')...
            && ~strcmp(ncnames(theVars{i}),'lon') && ~strcmp(ncnames(theVars{i}),'lat')...
            &&  ~strcmp(ncnames(theVars{i}),'depth') &&  ~strcmp(ncnames(theVars{i}),'burst' ))
        data = theVars{i}(:);
        [row, col] = size(data);
        mins = zeros(1,col);
        maxs = zeros(1,col);
        if col == 1,
            theVars{i}.minimum = ncfloat(gmin(data));
            theVars{i}.maximum = ncfloat(gmax(data));
            % elseif col == 2,
        elseif col == 2,
            theVars{i}.minimum = ncfloat(gmin(gmin(data)));
            theVars{i}.maximum = ncfloat(gmax(gmax(data)));
        elseif col > 2, % then these are amp and cor or some other 3d var
        % this is clunky but gets a single min and max over all the bursts       
            mins = gmin(gmin(data));
            maxs = gmax(gmax(data));
            theVars{i}.minimum = ncfloat(gmin(mins'))';
            theVars{i}.maximum = ncfloat(gmax(maxs'));
        end
        clear mins maxs
    end
end
% update the creation date
nc.CREATION_DATE(:)=datestr(now);
history=nc.history(:);
ncatt('history',['corrected variable min and max:' sprintf('\n') history],nc);