如果文件不存在，如何從導入中跳過文件？

Question

tarFileNames包含需要導入的所有文件的名稱。某些文件可能不存在。我怎麼能跳過不存在這樣的文件，循環就不會與此錯誤停止：

Error using imread (line 349) 
File "C:\Users\xyz.tif" does not exist. 

代碼：

for m = 1:length(tarFileNames) 
    tarConus = imread(tarFileNames{m}); 
    tarConus(end,:) = []; % Dropping last col and row from each page 
    tarConus(:,end) = []; 
    tarAccum = plus(tarConus(select),tarAccum); 
end 

Answer 1

您可以檢查使用exist文件的存在。請務必指定第二個輸入參數，它指定您只想按該名稱查找文件。

%// Determine all of the files that don't exist. 
doesExist = cellfun(@(x)exist(x, 'file') == 2, tarFileNames); 

%// File which do not exist 
invalidNames = tarFileNames(~doesExist); 

%// File which do exist 
validNames = tarFileNames(doesExist); 

%// Only loop through the ones that do exist 
for m = 1:numel(validNames)  
    tarConus = imread(validNames{m}); 
    tarConus(end,:) = []; % Dropping last col and row from each page 
    tarConus(:,end) = []; 
    tarAccum = plus(tarConus(select),tarAccum); 
end 

Answer 2

if exist(Name, 'file')回報2文件是否存在，或者如果7存在一個文件夾。

對不起，目前沒有matlab可用於爲您編寫和測試完整的代碼。

我想這應該是類似的東西：

for m = 1:length(tarFileNames) 
    if exists(tarFileNames{m}, 'file') 
     tarConus = imread(tarFileNames{m}); 
     tarConus(end,:) = []; % Dropping last col and row from each page 
     tarConus(:,end) = []; 
     tarAccum = plus(tarConus(select),tarAccum); 
    else 
    end 
end 

Answer 3

exist()可以檢查文件是否存在。這應該這樣做：

for m = 1:length(tarFileNames) 
    if exist(tarFileNames{m}, 'file') 
     tarConus = imread(tarFileNames{m}); 
     tarConus(end,:) = []; % Dropping last col and row from each page 
     tarConus(:,end) = []; 
     tarAccum = plus(tarConus(select),tarAccum); 
    end 
end