How to delete and change string in cell array?

Hi, I have a cell array with every cell containing a string for every day such as: 1313406900.Mon.Aug.15_11_15_00.GMT.2011.nordzee1.cx.plan.bar

I want to change the strings on my cell array so it only give me the date, as Aug-15-2011 on the example. How can I delete the part of the string I'm not interested in?

Thanks in advance, Sara

Answer 1

[Azzi Abdelmalek]

s={'1313406900.Mon.Aug.15_11_15_00.GMT.2011.nordzee1.cx.plan.bar';'1313406900.Mon.Jun.17_12_15_00.GMT.2011.nordzee1.cx.plan.bar'}
out=datestr(regexpi(s,'(?<=[a-z]+\.)([a-z]+\.\d+_\d+)','match','once'),'dd-mmm-yyyy')

Answer 2

[Guillaume]

On the assumption that the first _ is always between the day and the year, and that the year is always 20xx, and that the month is always before a dot immediately before the day:

regexprep(yourcellarray, '.*?([^.]+)\.(\d+)_(\d+).*', '$1-$2-20$3')

will work. The regular expression has five parts:

• .*? is intended to match everything before the month. It matches any number of characters but as few as possible so that the rest of the expression still matches
• ([^.]+)\. is intended to capture the month. It matches the longest sequence of non-dot characters followed by a dot. The sequence of non-dot character is token number 1
• (\d+)_ is intended to capture the day. It matches as many digits as possible followed by a _. The digit sequence is token number 2
• (\d+) is intended to capture the year. It matches as many digits as possible. This is token number 3
• .* matches the remainder of the string

Tokens 1,2 and 3 are simply strung together with a - in between and a 20 before token 3. The rest of the match is discarded.