is there an easy way to import data separated by brackets

Question

Michael 2012-10-9

0
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https://ww2.mathworks.cn/matlabcentral/answers/50296-is-there-an-easy-way-to-import-data-separated-by-brackets

采纳的回答： per isakson

在 MATLAB Online 中打开

I have some data in this form:

((0,0),(0.1,5),(0.2,7.5))

anyone have any idea how to import it? i would like it in a matrix in the form of

  0
1  5
2  7.5

Thanks for your help

Mike

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Michael 2012-10-9

sorry i've just seen how useless this looks i want it in the form [0,0;0.1,5;0.2,7.5]

per isakson 2012-10-9

编辑：per isakson 2012-10-9

"import" implies text file?
the text file contains several rows?
does your comment imply that the result shall be a <3x2xnumber_of_lines > double array?

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Answer 1

per isakson 2012-10-9

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/50296-is-there-an-easy-way-to-import-data-separated-by-brackets#answer_61421

编辑：per isakson 2012-10-11

在 MATLAB Online 中打开

Hint:

    str = '((0,0),(0.1,5),(0.2,7.5))';
    M   = textscan( str, '%f%f%f%f%f%f' ...
                , 'Delimiter', ','      ...
                , 'Whitespace', '() '   ...
                , 'CollectOutput', true );
    >> M{:}
    ans =
             0         0    0.1000    5.0000    0.2000    7.5000
    >>

and reshape

    >> transpose(reshape( M{:}, [2,3]))
    ans =
             0         0
        0.1000    5.0000
        0.2000    7.5000

.

replace str by a file id

    fid = fopen( ...
    M   = textscan( fid, ...

.

--- reading from file ---

    fid = fopen( 'cssm.txt' );
    M   = textscan( fid, '%f'            ...
                ,   'Delimiter'  , ','   ... 
                ,   'Whitespace' , '() ' ...   
                , 'CollectOutput', true  );
    fclose( fid );

permute( reshape( M{:}, 2,3,4 ), [ 2,1,3 ] )

permute( reshape( M{:}, 2,3,[]), [ 2,1,3 ] )

where cssm.txt contains

    ((0,0),(0.1,5),(0.2,7.5))
    ((1,1),(0.1,5),(0.2,7.5))
    ((2,2),(0.1,5),(0.2,7.5))
    ((3,3),(0.1,5),(0.2,7.5))

outputs

    ans(:,:,1) =
             0         0
        0.1000    5.0000
        0.2000    7.5000
    ans(:,:,2) =
        1.0000    1.0000
        0.1000    5.0000
        0.2000    7.5000
    ans(:,:,3) =
        2.0000    2.0000
        0.1000    5.0000
        0.2000    7.5000
    ans(:,:,4) =
        3.0000    3.0000
        0.1000    5.0000
        0.2000    7.5000

.

--- a variation ---

    fid = fopen( 'cssm.txt' );
    M   = textscan( fid, '%f'                           ...
                ,   'Delimiter'             , ',() '    ... 
                ,   'MultipleDelimsAsOne'   , true      ...
    ...         ,   'Whitespace'            , '() '     ...   
                ,   'CollectOutput'         , true      );
    fclose( fid );
    permute( reshape( M{:}, 2,3,[] ), [ 2,1,3 ] )

.

Comment: These constructs does not use the information hold by the parentheses. Furthermore, there is not test that the file confirms to the assumed format. With some clever use of regular expressions it would be possible to make a more robust code.