Textscan

Question

我正在尝试读入一堆文本文件。有一个日期栏。某些文件中日期列的格式为 DD-MMM-YYYY，而在其他文件中为 DD-MM-YYYY。我已将代码设置为读取第一种样式。但正因为如此，如果它遇到第二种类型，代码就会停止，因为它无法读取文件。我该怎么做，If thetextscandoesn'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

将所有内容包装在 try/catch 块中。如果第一种样式失败，请尝试下一种（请注意，我更改了 catch 部分中的日期格式。）如果您有更多的可能性，您将需要使用 [= 之类的东西检查每种样式13=] 子句。

Textscan - 捕获错误并尝试其他方法

Textscan - Catch error and try something else

matlab

date