Extracting certain data from very large text/numeric data

2013 8 28
2 个回答
更新时间：2021 8 20
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0 个投票

I am trying to extract data from a hoc file which is a combination of text,whitespace,characters, and numbers. I need to be able to find the row index of wherever there occurs the string "section[%d]" where d is an integer, just being able to find the row when I use importdata to a cell array would be good enough, there are upwards of like 40 occurences of the string so I need to find all of them.

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Cedric
Cedric 2013-8-28
Why do you need row numbers? What do you need to extract or do then with these row numbers?
Bernard
Bernard 2013-8-28
first of all you answered my last question about dealing with this and that was great. I had forgotten to mention that within all of the rows the points are parsed every now and then by a new "section" of points, so I need to be able to identify which point corresponds to the start of a new "section". If you recall the data for the most part is like
pt3dadd(x,y,z,d,e) pt3dadd(x1,y1,z1,d1,e1) } section[2] { pt3dadd(x2,... and so on
Bernard
Bernard 2013-8-28
  • pt3dadd(x,y,z,d,e)
  • pt3dadd(x1,y1,z1,d1,e1)
  • }
  • section[2] {
  • pt3dadd(x2,
Cedric
Cedric 2013-8-28
Kelly and I also answered this question from you:
http://www.mathworks.com/matlabcentral/answers/84367-ridiculously-simple-nearest-neighbor-search-3d
but you gave no feedback, did you need more information?
For the current question, do you need to get the section ID or just to split the file by section and process each section with TEXTSCAN ?
Bernard
Bernard 2013-8-29
This is not anything to do with calculation. I need to just find where in the text the section id string occurs because that will give me a reference for the first point in that section. The ID number doesn't matter that much since if there is section written 10 times throughout all the points it will be sections(1-10)
Walter Roberson
Walter Roberson 2013-8-29
My regexp solution is not working for you?

回答（2 个）

Walter Roberson
Walter Roberson 2013-8-28

0 个投票

find(~cellfun(@isempty, regexp(YourCell, 'section\[%\d+\]', 'start')))
Cedric
Cedric 2013-8-29
编辑：Cedric 2013-8-29

0 个投票

Based on your comment: one way to tackle that is to split the file according to section headers/footer, so you get blocks that you can process using TEXTSCAN. Example:
content = fileread('myData.txt') ;
blocks = regexp(content, '(}\s*){0,1}section\[\d+\]\s*{|}', 'split') ;
blocks = blocks(2:end-1) ; % Eliminate first empty and last
% (after last '}') blocks.
nBlocks = length(blocks) ;
data = cell(nBlocks, 1) ;
for bId = 1 : nBlocks
data{bId} = textscan(blocks{bId}, 'pt3dadd(%f,%f,%f,%f,%f)') ;
end
and if you don't want data to be a cell array of cell arrays (output of _TEXTSCAN_is a cell array of columns), you can replace the above line in the FOR loop with:
buffer = textscan(blocks{bId}, 'pt3dadd(%f,%f,%f,%f,%f)') ;
data{bId} = [buffer{:}] ;

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Bernard
Bernard
2013-8-28

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