function [mvals]=get_whfc_meta(url);
% GET_WHFC_META  Get lon,lat,start,stop from an WHFC time series file
% return a structure of useful stuff for future use
% RPS & ETM 9/07
%
% etm 3/2010  modified to use mDataset from njtools instead of using a
% DAP-enabled netcdf (requiring avery old mexnc_dap_r14)
% mDataset doesn't get all the global attributes- important to this program
% are .longitude, .latitude, and .WATER_DEPTH
%

% Could use mdataset for web resources, use netcdf for local, but am trying
% to do it all with mDataset
if(strncmp(url(end),'<',1))
    url=url(1:end-1);
end
% can't do burst files since no lat and lon coords
if ~isempty(strfind(url,'b-cal'))
    mvals=[];
    disp(['skipping ' url])
else
disp(url)
nc=mDataset(url)      % uses njTools- doesn't work fully Apr. 2010
%nc=netcdf(url);         % old way uses mexnc_linux_r14_dap/mexnc.mexglx
if isempty(nc)
    respns=input('there is nothing in nc- want to continue? ','s')
    if strncmp(lower(respns),'n',1)
        disp('exiting program')
        return
    end
end
mvals.lon=nc{'lon'}(1);
mvals.lonmeta=nc.longitude(:);
mvals.lat=nc{'lat'}(1);
mvals.latmeta=nc.latitude(:);
% get the instrument type if available
if isempty(nc.INST_TYPE(:))
    mvals.sensr='unavailable';
else
    mvals.sensr=nc.INST_TYPE(:);
end

% Determine if uniform time base by checking if
%      dt*(nt-1) = t(end)-t(1)
% Why use dt=(t(3)-t(1))/2 instead of dt=t(2)-t(1)?
% Good question.  Because in the first dataset I tried
% (MYRTLEBEACH/7201adc-a.nc), t(2) was off by 1 millisecond.
% Do exact math in integers (milliseconds)

ntimes=length(nc{'time'}(:));
d1=double(nc{'time'}(1));       % having these as double is necessary
d3=double(nc{'time'}(3));       % when netcdf-java is used.
d99=double(nc{'time'}(end));
e1=double(nc{'time2'}(1));
e3=double(nc{'time2'}(3));
e99=double(nc{'time2'}(end));
if isnan(e99)
    d99=double(nc{'time'}(ntimes));
    e99=double(nc{'time2'}(ntimes));
end

% in this program, d?=the day part of the EPIC time, e? is the parts of the
% day or "time" component (based on EPIC time2).

% round time2 values to nearest second to cover for previous sins
% in processing which have led to 1 millisecond errors
t1=round(e1/1000)*1000;

t3=(d3-d1)*3600*24*1000+round(e3/1000)*1000;
tend=(d99-d1)*3600*24*1000+round(e99/1000)*1000;
dt=(t3-t1)/2;

% Express start/stop times in Matlab datenum
%  so datestr(mvals.jd_start) returns an answer that matches
%    gregorian(nc{'time'}(1)+(nc{'time2'}(1)/86400000))
%  1721059 is a factor that allows our julian day 2440000 that begin at
%  0000 hours, May 23, 1968. to be used with datenum
mvals.jd_start=(d1 - 1721059)+t1/3600/24/1000;
mvals.jd_stop=(d1 - 1721059)+tend/3600/24/1000;
mvals.mjd_start=(d1 - 1721059)*3600*24*1000 + t1;
mvals.mjd_stop =(d1 - 1721059)*3600*24*1000 + tend;  % fixed typo here
tot1=dt*(ntimes-1);
tot2=tend-t1;
if tot1==tot2,
    mvals.timebase_uniform=1;
    mvals.dt=dt/1000;  % dt in milliseconds
    mvals.dtms=dt;  % dt in milliseconds
else
    mvals.timebase_uniform=0;
end
% use WATER_DEPTH (1st) or water_depth (if WATER_DEPTH missing) attribute
if isempty(nc.WATER_DEPTH(:))
    if isnumeric(nc.water_depth(:))
        mvals.wdep=nc.water_depth(:);
    else
        mvals.wdep='missing';
    end
else
    mvals.wdep=nc.WATER_DEPTH(:);
end
mvals.meas_dep=nc{'depth'}(:);
% ncnames doesn't work with mDatset
%mvals.varnames=ncnames(var(nc));
mvals.varnames=getVarNames(nc);
for ik=1:length(mvals.varnames)
    eval(['mvals.long_names{ik} = nc{''' mvals.varnames{ik} '''}.long_name(:);'])
end
close(nc);
end