Search number in one cell of a csv file

Question

Stefan Langlouis 2019-1-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/440713-search-number-in-one-cell-of-a-csv-file

评论： StefBu 2019-1-22

采纳的回答： StefBu

header_csv.PNG

在 MATLAB Online 中打开

Hi everybody,

I'm reading the header of an csv-file and want to get the numbers to a new variable for my fft.

My problem is, that the header is in one cell. ->See the header_csv.png

At the moment i read the whole header with this code i've found online:

fid = fopen('acq0003.csv', 'r');
header = textscan(fid, '%[^,],%[^,],%[^,\r\n]', 3);
data = transpose(fscanf(fid, '%g,%g,%g\n', [2, Inf]));
fclose(fid);
%Note that the data read by fscanf need to be transposed (I emphasized this by writing transpose instead of '). 
for i = 1 : 3; disp(['#' cell2mat(header{i})]); end;
disp(data);

that works. But now I want to scan for the text "samples" and the "sample-rate" to get the following numbers as values for my fft.

Any idea how i can scan for these particular values?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

StefBu 2019-1-21

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/440713-search-number-in-one-cell-of-a-csv-file#answer_357344

编辑：StefBu 2019-1-21

在 MATLAB Online 中打开

Try this code. It should work for you. If not feel free to ask.

Greetings

Stefan

% Get data from cell
head = header{1,1}{1,1};
% Define strings for search 
NameStart       = '#Sample rate: ';
LengthNameStart = length(NameStart);
NameEnd         = 'Hz';
LengthNameEnd   = length(NameEnd) - 1; % 
% Determine indexes for string exctraction 
StringStart = strfind(head, NameStart) + LengthNameStart;
StringEnd   = strfind(head, NameEnd) - LengthNameEnd;
% Exctract string and convert to double
SampleRate = str2double(head(StringStart:StringEnd));

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Stefan Langlouis 2019-1-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/440713-search-number-in-one-cell-of-a-csv-file#answer_357371

Yep it's working :) Thank you very much!

But just for the sake of understanding, I call the expression "/ n" for "NameEnd" if I did not have any text ending like Hz? Or how do i finisch the string then