How do I read in a text file and sort it by a column

5 次查看（过去 30 天）
Aaron
Aaron 2013-10-10
评论： sixwwwwww 2013-10-12
I have a file which I am trying to read and then sort by column A and then by column C. The text file is attached and has 3 columns. This is what I have tried but it will not let me use the sort function after reading it in this way:
function data = ResultsScript(filename)
fid = fopen(filename);
data = textscan(fid, '%s %f %f');
fclose(fid);
end
Then I call this function and try to sort it using:
fileName = 'Example.txt';
A = ResultsScript(fileName);
sortrows(A,[1,3]);
Running this gives the following error message:
??? Index exceeds matrix dimensions.
Error in ==> sortrows>sort_cell_back_to_front at 133
ndx = ndx(ind);
Error in ==> sortrows at 90
ndx = sort_cell_back_to_front(x_sub, col);
Error in ==> GetResults at 3
sortrows(A,[1,3]);
Any help is greatly appreciated.

请先登录，再回答此问题。

采纳的回答

sixwwwwww
sixwwwwww 2013-10-12
Dear Aaron, the problem here is that function "textscan" output data in the form of cell array which you must convert first into a matrix before using "sortrows" function because "sortrows" only accept vector or matrix data. So after converting it to proper form you can apply "sortrows". Also don't use "%s" to read values of double type instead use "%f" or better "%n". Following is the corrected code for this purpose:
fid = fopen(filename);
cell_data = textscan(fid, '%n %n %n');
fclose(fid);
matrix_data = [cell_data{:}];
After this you can apply:
sorted_data = sortrows(matrix_data, [1 3]);
  2 个评论
Aaron
Aaron 2013-10-12
Thank you very much for you help! And the first column of data isn't actually a double, it is a hexadecimal number. An EPC from a RFID tag.
sixwwwwww
sixwwwwww 2013-10-12
You are welcome and sorry for misunderstanding about EPC because I don't know about EPC.

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Text Files 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by