Textscan - 抓取錯誤，並嘗試其他的東西

Question

我想讀一堆文本文件。有一個日期欄。日期列的某些文件中的格式爲DD-MMM-YYYY，而在其他文件中的格式爲DD-MM-YYYY。我已經設置了代碼來讀取第一個樣式。但是因爲如此，如果它運行到第二種類型，代碼會停止，因爲它無法讀取文件。我該怎麼做，If the textscan doesn't work, try this second way？

for n = 1:length(data1{id}) 
    fname1 = char(data1{id}(n)); 
    delimiter = '\t'; 
    startRow = 2; 
    formatSpec = '%s%f%f%f%s%s%s%s%{dd-MMM-yyyy}D%s%s%f%f%f%f%f%f%s%s%s%s%s%s%s%s%f%f%[^\n\r]'; 
    fileID = fopen(fname1,'r'); 
    dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'EmptyValue' ,NaN,'HeaderLines' ,startRow-1, 'ReturnOnError', false, 'EndOfLine', '\r\n'); 
    fclose(fileID); % Close the text file. 
    PM25_1{id}{n} = table(dataArray{1:end-1}, 'VariableNames', {'MonitorID','POC','Latitude','Longitude','Datum','ParameterName','SampleDuration','PollutantStandard','DateLocal','UnitsofMeasure','EventType','ObservationCount','ObservationPercent','ArithmeticMean','FirstMaxValue','FirstMaxHour','AQI','MethodName','LocalSiteName','Address','StateName','CountyName','CityName','CBSAName','DateofLastChange','DateNum','NumberOfPOCs'}); 
    clearvars filename delimiter startRow formatSpec fileID dataArray ans; 
end 

Answer 1

try 

for n = 1:length(data1{id}) 
    fname1 = char(data1{id}(n)); 
    delimiter = '\t'; 
    startRow = 2; 
    formatSpec = '%s%f%f%f%s%s%s%s%{dd-MMM-yyyy}D%s%s%f%f%f%f%f%f%s%s%s%s%s%s%s%s%f%f%[^\n\r]'; 
    fileID = fopen(fname1,'r'); 
    dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'EmptyValue' ,NaN,'HeaderLines' ,startRow-1, 'ReturnOnError', false, 'EndOfLine', '\r\n'); 
    fclose(fileID); % Close the text file. 
    PM25_1{id}{n} = table(dataArray{1:end-1}, 'VariableNames', {'MonitorID','POC','Latitude','Longitude','Datum','ParameterName','SampleDuration','PollutantStandard','DateLocal','UnitsofMeasure','EventType','ObservationCount','ObservationPercent','ArithmeticMean','FirstMaxValue','FirstMaxHour','AQI','MethodName','LocalSiteName','Address','StateName','CountyName','CityName','CBSAName','DateofLastChange','DateNum','NumberOfPOCs'}); 
    clearvars filename delimiter startRow formatSpec fileID dataArray ans; 
end 

catch 

for n = 1:length(data1{id}) 
    fname1 = char(data1{id}(n)); 
    delimiter = '\t'; 
    startRow = 2; 
    formatSpec = '%s%f%f%f%s%s%s%s%{dd-MM-yyyy}D%s%s%f%f%f%f%f%f%s%s%s%s%s%s%s%s%f%f%[^\n\r]'; 
    fileID = fopen(fname1,'r'); 
    dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'EmptyValue' ,NaN,'HeaderLines' ,startRow-1, 'ReturnOnError', false, 'EndOfLine', '\r\n'); 
    fclose(fileID); % Close the text file. 
    PM25_1{id}{n} = table(dataArray{1:end-1}, 'VariableNames', {'MonitorID','POC','Latitude','Longitude','Datum','ParameterName','SampleDuration','PollutantStandard','DateLocal','UnitsofMeasure','EventType','ObservationCount','ObservationPercent','ArithmeticMean','FirstMaxValue','FirstMaxHour','AQI','MethodName','LocalSiteName','Address','StateName','CountyName','CityName','CBSAName','DateofLastChange','DateNum','NumberOfPOCs'}); 
    clearvars filename delimiter startRow formatSpec fileID dataArray ans; 
end 

end 

裹一切都在一個try/catch塊。如果第一個樣式失敗，請嘗試下一個樣式（請注意，我更改了catch部分中的日期格式。）如果您有更多可能性，則需要使用if/else子句等方式檢查每種樣式。