Convert an array of timestamps to seconds in Matlab - arrays

Question

I'm new to SO and Matlab so please excuse any transgressions.
I'm trying to convert a seemingly simple array of timestamp strings to an equivalent array of seconds.
I wrote a this function:
% Function to calculate seconds from a timestamp in the following format:
% ddd hh:mm:ss.SSSS (example: 123 12:59:00.9999)
function a = TimestampToS(stamp)
% Uses the "named tokens" facility of MATLAB's "regexp" function.
expr = ['(?<ddd>\d+)' ... % ddd
' ' ... % Space " " separator
'(?<hh>\d+)' ... % hh
':' ... % Colon ":" separator
'(?<mm>\d+)' ... % mm
':' ... % Colon ":" separator
'(?<ss>\d+)' ... % ss
'.' ... % Dot "." separator
'(?<SSSS>\d+)']; % SSSS
parsedStamp = regexp(stamp, expr, 'names');
a = (str2double(parsedStamp.ddd) * 86400) + ...
(str2double(parsedStamp.hh) * 3600) + ...
(str2double(parsedStamp.mm) * 60) + ...
(str2double(parsedStamp.ss)) + ...
(str2double(parsedStamp.SSSS) * 0.0001);
It works great for an individual string:
>> TimestamptoS('123 12:59:00.9999')
ans =
1.067394099990000e+007
But if I try to use a cell array I get:
Attempt to reference field of non-structure array.
How can I get an array of seconds? I have tried all kinds of conversions of the input data and "parsedStamp" but nothing works. I don't understand Matlab or its matrix notation well enough. Any help gratefully received!
PS This is not a regexp question, no replies about regexp please!

Answer 1

You can do it very easily without modifying your function, by using cellfun. This essentially extracts each cell of the cell array and passes it to your function.
>> cellArray = {'123 12:59:00.9999','130 12:59:00.9999'}; % for example
>> cellfun(#TimestampToS,cellArray)
ans =
1.0e+007 *
1.067394099990000 1.127874099990000