Read data from .txt with regexp

Question

Aurea94 2022-3-29

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1683494-read-data-from-txt-with-regexp

评论： Rik 2022-4-18

ExampleTextFile.txt

I want to load numeric data from a .txt file, which contains both string a numeric and contains non standard arranging. I am attaching an example file for you to see.

The data is divided in sections, but all the numeric data I am interested in have the same structure: '->' + 'some string' + ':' + 'numeric value with format %.4f' (Lines in the .txt not containing the desired expression should not be considered).

I tested different manners of doing so, with readfile, testscan etc., however due to the complexitu of the input file I could not reach my objective.

I think the most appropiate way to try to solve the problem is by using regexp and properly telling matlab which is the expression it has to look for in the .txt file.

I am not familarised with regexp and cannot properly understand how to code the proper expression for me to work, and would greatly appreaicate any help with that.

Thank you very much!

============================================================================
|                     DATA VALUES FOR INPUT VARIABLES                      |
============================================================================
Model: Example
(data file produced by on 29-Mar-2022 17:30:14) 
============================================================================
FIRST DATA SECTION:
============================================================================
-> z [val]: 13.0000
-> m [in mm]: 3.0000
-> Type [str]: Ball
-> c_s [valval]: 0 0 0
----------------------------------------------------------------------------
SECOND DATA SECTION:
============================================================================
-> r_b [strandnumber]: C50
-> s0_r [in mm]: 0.0000
-> I_r [val]: 15.0000
-> Only text line
----------------------------------------------------------------------------
THIRD DATA SECTION:
============================================================================
-> Values found = 0.
----------------------------------------------------------------------------
FOURTH DATA SECTION:
============================================================================
-> n_1 [val_1]: 1.0000

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Aurea94 2022-3-30

Yes that was really really fantastic!!

Rik 2022-3-30

For basic data like this, even JSON should be preferred. Just about every half-decent programming language can read it. Composing matrices is a bit tricky, but as long as you stick to scalars or vectors everything should be fine.

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Answer 1

Stephen23 2022-3-29

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1683494-read-data-from-txt-with-regexp#answer_929814

编辑：Stephen23 2022-3-29

在 MATLAB Online 中打开

ExampleTextFile.txt

rgx = '^\s*->\s*(\w+)\s*\[[\w\s]+\]:\s*([^\r\n]+)';
str = fileread('ExampleTextFile.txt');
tkn = regexp(str,rgx,'tokens','lineanchors');
tkn = vertcat(tkn{:})
tkn = 8×2 cell array
    {'z'   }    {'13.0000'}
    {'m'   }    {'3.0000' }
    {'Type'}    {'Ball'   }
    {'c_s' }    {'0 0 0'  }
    {'r_b' }    {'C50'    }
    {'s0_r'}    {'0.0000' }
    {'I_r' }    {'15.0000'}
    {'n_1' }    {'1.0000' }
vec = str2double(tkn(:,2));
idx = ~isnan(vec);
tkn(idx,2) = num2cell(vec(idx))
tkn = 8×2 cell array
    {'z'   }    {[   13]}
    {'m'   }    {[    3]}
    {'Type'}    {'Ball' }
    {'c_s' }    {'0 0 0'}
    {'r_b' }    {'C50'  }
    {'s0_r'}    {[    0]}
    {'I_r' }    {[   15]}
    {'n_1' }    {[    1]}
out = cell2struct(tkn(:,2),tkn(:,1),1)
out = struct with fields:
       z: 13
       m: 3
    Type: 'Ball'
     c_s: '0 0 0'
     r_b: 'C50'
    s0_r: 0
     I_r: 15
     n_1: 1

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Md Kamrul Hasan Ikbal 2022-4-18

@Stephen; Can I get your email. I need a favour from you.

Rik 2022-4-18

I expect your chances would be much better if you posted your request as a separate question and post the link here. People tend to be protective of their inbox.

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