I’ve had a few people ask recently if I have a matlab utility to concatenate several 20-Hz data files. Below is a script that should do that, and keep the 20-Hz data format that you are used to working with.
You will need to adjust the first few lines (file location, files names) to your situation. Make sure that the first file in the list has the first data, as all of the sonic timestamps will be based off the first timestamp in that file.
[code]directory = ‘~/Downloads’;
files = {‘03254_14_20_00_009.mat’; …
‘03254_14_30_00_009.mat’;…
‘03254_14_40_00_059.mat’};
nfiles = length(files);
% initalize the array that we will dump data into
data = struct;
datanew = struct;
for f = 1:nfiles
datain = load(fullfile(directory, files{f}));
if f == 1
datanames = fieldnames(datain);
newnames = datanames;
end
% work through each of the elements so that we can catch special cases
for n = 1:length(datanames)
if strcmp(datanames{n},‘tower’)
% ignore this field
newnames{n} = ‘’;
else
if strfind(datanames{n},‘dt’)
% need to change dt so it’s a UTC time instead
newnames{n} = strrep(datanames{n},‘dt’,‘timestamp’);
datanew.(newnames{n}) = struct(‘val’, datain.time_UTC.val(1)+datain.(datanames{n}).val,…
‘label’,datain.(datanames{n}).label,…
‘units’,datain.(datanames{n}).units,…
‘height’,datain.(datanames{n}).height);
else
datanew.(newnames{n}) = struct(‘val’,datain.(datanames{n}).val,…
‘label’,datain.(datanames{n}).label,…
‘units’,datain.(datanames{n}).units,…
‘height’,datain.(datanames{n}).height);
end
end
end
% append the new data to the old data
if f == 1
data = datanew;
else
for n = 1:length(newnames)
if ~isempty(newnames{n})
data.(newnames{n}).val = vertcat(data.(newnames{n}).val,…
datanew.(newnames{n}).val);
end
end
end
end
[/code]
plotting then works the same as always.
%% plot some data
figure
plot(data.Sonic_timestamp_clean_100m.val,...
data.Sonic_x_clean_100m.val,'k.')