八度/ Matlab-读取固定宽度的文件

Question

I have a fixed width file format (original was input for a Fortran routine). Several lines of the file look like the below:

1078.0711005.481 932.978 861.159 788.103 716.076

How this actually should read:

1078.071 1005.481 932.978 861.159 788.103 716.076

I have tried various methods, textscan, fgetl, fscanf etc, however the problem I have is, as seen above, sometimes because of the fixed width of the original files there is no whitespace between some of the numbers. I cant seem to find a way to read them directly and I cant change the original format.

The best I have come up with so far is to use fgetl which reads the whole line in, then I reshape the result into an 8,6 array

A=fgetl
A=reshape(A,8,6)

which generates the following result

11
009877
703681
852186
......
049110
787507
118936

So now I have the above and thought I might be able to concatenate the rows of that array together to form each number, although that is seeming difficult as well having tried strcat, vertcat etc.

All of that seems a long way round so was hoping for some better suggestions.

Thanks.

Answer 1

If you can rely on three decimal numbers you can use a simple regular expression to generate the missing blanks:

s = '1078.0711005.481 932.978 861.159 788.103 716.076';
s = regexprep(s, '(\.\d\d\d)', '$1 ');
c = textscan(s, '%f');

Now c{1} contains your numbers. This will also work if s is in fact the whole file instead of one line.

Answer 2

You haven't mentioned which class of output you needed, but I guess you need to read doubles from the file to do some calculations. I assume you are able to read your file since you have results of reshape() function already. However, using reshape() function will not be efficient for your case since your variables are not fixed sized (ie 1078.071 and 932.978).

If I did't misunderstand your problem:

1. Your data is squashed in some parts (ie 1078.0711005.481 instead of 1078.071 1005.481).

2. Fractional part of variables have 3 digits.

First of all we need to get rid of spaces from the string array:

A = A(~ismember(A,' '));

Then using the information that fractional parts are 3 digits:

iter = length(strfind(A, '.'));
for k=1:iter   
    [stat,ind] = ismember('.', A);
    B(k)=str2double(A(1:ind+3));
    A = A(ind+4:end); 
end

B will be an array of doubles as a result.