使用 space 分隔符将文件导入 MATLAB 元胞数组

Question

我有一个 .asc 文件 'test.asc'，它由不同长度和内容的行组成。

  my name is blalala
  This is my home and I live in here
  12 13 10 is he
  he is my brother 12 13 14

如何将文件的内容导入到每行由 space 分隔符分隔的一行的 MATLAB 元胞数组中？

  resultCellarray={
    'my'   'name' 'is'  'blalala' []    []   []     []   []
    'This' 'is'   'my'  'home'    'and' 'I' 'live' 'in' 'here'
    '12'   '13'   '10'  'is'      'he'  []   []     []   []
    'he'   'is'   'my'  'brother' '12' '13'  '14'   []   []
    }

我试过将每一行作为一个单元格插入：

   content = textread('test.asc','%s','delimiter','\n','whitespace','');

然后将单元格分成几列，使用：，但是当文件很大时，它会花费很多时间。最快的方法是什么？

Answer 1

此代码应该运行非常快（在 0.2 秒内拆分 1M 个字符）：

%generate random file
% w=[10,13,32*ones(1,10),97:122,97:122];
% FILE_LENGTH=10*1000*1000;mytext=char(w(randi(length(w),1,FILE_LENGTH))); 
% fileID = fopen('z:\mytest.asc','w');fprintf(fileID,'%s',mytext);fclose(fileID);
clear
tic
%settings
Filename='z:\test.asc';
LineDelimiter=newline;%=char(10)
WordDelimiter=' ';

%read file
fid=fopen(Filename,'r');
text=fread(fid,'*char')';
fclose(fid);

%fix text
text(text==char(9))=WordDelimiter; %replace tab with space
text(text==char(13))=[];%remove '\r'
if text(end)~=LineDelimiter, text(end+1)=LineDelimiter;end %add eol if needed
IdxWords=find(text==WordDelimiter);
text(IdxWords(diff(IdxWords)==1))=[];% remove 2 spaces or more

%count words per line
IdxNewline=find(text==LineDelimiter);
NumOfLines=length(IdxNewline); %2eol=2lines
WordsPerLine=zeros(1,NumOfLines); %
IdxWords=find(text==WordDelimiter|text==LineDelimiter);
iword=1; iword_max=length(IdxWords);
for i=1:NumOfLines
    while iword<=iword_max && IdxWords(iword)<=IdxNewline(i)
        WordsPerLine(i)=WordsPerLine(i)+1;
        iword=iword+1;
    end
end
MaxWords=max(WordsPerLine);
LongestWord=max(diff(IdxWords));

%split
Output=cell(NumOfLines,MaxWords);
pos=1;iword=0;
for i=1:NumOfLines
    idxline=IdxNewline(i);
    for j=1:WordsPerLine(i)
        iword=iword+1;
        Output{i,j}=text(pos:IdxWords(iword)-1);
        pos=IdxWords(iword)+1;
    end
end
toc

% disp(Output)

使用 space 分隔符将文件导入 MATLAB 元胞数组

Import file into MATLAB cell array with space delimiter

matlab

textreader

cell-array