How to check if a ,MDF file is unsorted?

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Serbring
Serbring 2019년 10월 6일
댓글: Serbring 2019년 10월 29일
Hi all,
I am trying to read on matlab several .MDF files. All of them are exported with the some tool and for some reasons, some of them are unsorted. I need to know which files are unsorted. Is there any way to do that?
Here is my code. If a file is unsorted I get an error when I read the file, so I added the two lines which sort the files (the two under comment), but in that case, if the file is sorted, I get an error at the mdfSort function. By knowing which files are unsorted, I can solve the problem with a If-statement.
for iFile=1:length(MDFFile)
Duration=-1;
% sortedPath = mdfSort([MDFFolder MDFFile(iFile).name],'SortedMDFFile.mdf');
% mdfObj = mdf('SortedMDFFile.mf4');
mdfObj = mdf([MDFFolder MDFFile(iFile).name]);
if isempty(mdfObj.ChannelNames)==0
chlist = channelList(mdfObj);
chlistS=table2struct(chlist);
chlistName=convertStringsToChars([chlistS.ChannelName]);
for iSig=1:length(Signals2Load)
iCh=find(strcmp(chlistName,Signals2Load{iSig}));
if isempty(iCh)==0
data = read(mdfObj,chlistS(min(iCh)).ChannelGroupNumber,Signals2Load{iSig});
if Duration<0
Duration=seconds(floor(max(data.Time)));
CanData(iFile).Time=[0:TS:Duration];
end
CanData(iFile).(Signals2Load{iSig})=pchip(seconds(data.Time),data.(Signals2Load{iSig}),CanData(iFile).Time);
end
end
else
warning(['Problems in loading ' MDFFile(iFile).name])
end
end
  댓글 수: 2
Serbring
Serbring 2019년 10월 6일
Probably I have to. I do not like that much try/catch. In my opinion, it is not a synonim of good practice. Thanks.

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채택된 답변

Elliott Blocha
Elliott Blocha 2019년 10월 29일
The MDF file format specifies that "finalized" MDF files must start with "MDF " in the first 8 bytes (including the 5 spaces). In hex this is:
4D 44 46 20 20 20 20 20
Unfinalized (including unsorted) MDF files have "UnFinMF " in the first 8 bytes (including the 1 space). In hex this is:
55 6E 46 69 6E 4D 46 20
Look into the "fopen" and "fread" functions to check for the "finalized" flag.
mdfSort might already do this check, so it may be faster to use a try/catch statement.
  댓글 수: 1
Serbring
Serbring 2019년 10월 29일
Hi!
Thanks for your answer!!!

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