problem in reading datetime

Question

lina 2015-6-21

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回答： dpb 2015-6-21

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HI ALL

I Got a problem in reading string data file, the error is

??? Error using ==> textscan Invalid file identifier. Use fopen to generate a valid file identifier.

and the command which I used is

 fid=fopen('ARBY STARL 170310-200514 LT Edited_OBS TIDES 6mins.dat','r','n','ARAB');
s=textscan(fid,'%{dd MMMM yyyy hh:mm}D %f %f','DateLocale','Delimiter',',');
fclose(ARBY STARL 170310-200514 LT Edited_OBS TIDES 6mins);

finally, my data type is

May 2012 04:20,02.650
May 2012 04:25,02.640
May 2012 04:30,02.630
May 2012 04:35,02.630

anyone can help?

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Answer 1

dpb 2015-6-21

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The file wasn't opened successfully as the error says...use the alternate return to find out additional information on why...

[fid,msg]=fopen('ARBY STARL 170310-200514 LT Edited_OBS TIDES 6mins.dat','r','n','ARAB')

and see what the error message is for hints. I note the character code is not in the listed options so while Matlab will not error it will warn and may or may not provide a correct interpretation. I'd suggest unless there's a known reason, simply use the defaults other than for file permission although the most likely cause for fopen to fail is that the file is not located on the path and so simply isn't found. But, I'd still suggest

[fid,msg]=fopen('ARBY STARL 170310-200514 LT Edited_OBS TIDES 6mins.dat','rt')

as first go and check the returned handle is valid before going on to try to read anything 'cuz "it ain't agonna' work" until it is (valid that is).