matlab实现有序读取文件夹所有文件

2024-07-13 04:42| 来源: 网络整理| 查看: 265

1.问题：

matlab读取文件夹中的文件并不是按照有序读取，比如执行下面代码

jpgs = dir('E:\Code\matlab\figure_concat\fuse\*.png'); %读取当前目录下的所有文件，返回的jpgs是一个结构体

可以发现读取的文件的顺序不是从1到13，而是1 10 11 12.....这种。这对于某些需要按顺序读取文件的要求来说并不满足。这可咋办呢？难道根据名字一顿操作然后排序。其实这些早就有人遇到，并提供相应的函数解决了。下面说解决办法。

2.解决办法：

只需在执行sort_nat()就可以得到顺序的名字了。如下所示：

%读取当前目录下的所有文件，返回的jpgs是一个结构体 jpgs = dir('E:\Code\matlab\figure_concat\fuse\*.png'); jpgs_name=sort_nat({jpgs.name}); %大括号不可少哦。

我们发现此时的jpgs_name就是有序的名字了。jpgs_name是一个cell，此时按照cell方法调用对应名字就行。

sort_nat函数是mathworks中有人发布的。感恩。。

https://ww2.mathworks.cn/matlabcentral/fileexchange/10959-sort_nat-natural-order-sort

function [cs,index] = sort_nat(c,mode) %sort_nat: Natural order sort of cell array of strings. % usage: [S,INDEX] = sort_nat(C) % % where, % C is a cell array (vector) of strings to be sorted. % S is C, sorted in natural order. % INDEX is the sort order such that S = C(INDEX); % % Natural order sorting sorts strings containing digits in a way such that % the numerical value of the digits is taken into account. It is % especially useful for sorting file names containing index numbers with % different numbers of digits. Often, people will use leading zeros to get % the right sort order, but with this function you don't have to do that. % For example, if C = {'file1.txt','file2.txt','file10.txt'}, a normal sort % will give you % % {'file1.txt' 'file10.txt' 'file2.txt'} % % whereas, sort_nat will give you % % {'file1.txt' 'file2.txt' 'file10.txt'} % % See also: sort % Version: 1.4, 22 January 2011 % Author: Douglas M. Schwarz % Email: dmschwarz=ieee*org, dmschwarz=urgrad*rochester*edu % Real_email = regexprep(Email,{'=','*'},{'@','.'}) % Set default value for mode if necessary. if nargin < 2 mode = 'ascend'; end % Make sure mode is either 'ascend' or 'descend'. modes = strcmpi(mode,{'ascend','descend'}); is_descend = modes(2); if ~any(modes) error('sort_nat:sortDirection',... 'sorting direction must be ''ascend'' or ''descend''.') end % Replace runs of digits with '0'. c2 = regexprep(c,'\d+','0'); % Compute char version of c2 and locations of zeros. s1 = char(c2); z = s1 == '0'; % Extract the runs of digits and their start and end indices. [digruns,first,last] = regexp(c,'\d+','match','start','end'); % Create matrix of numerical values of runs of digits and a matrix of the % number of digits in each run. num_str = length(c); max_len = size(s1,2); num_val = NaN(num_str,max_len); num_dig = NaN(num_str,max_len); for i = 1:num_str num_val(i,z(i,:)) = sscanf(sprintf('%s ',digruns{i}{:}),'%f'); num_dig(i,z(i,:)) = last{i} - first{i} + 1; end % Find columns that have at least one non-NaN. Make sure activecols is a % 1-by-n vector even if n = 0. activecols = reshape(find(~all(isnan(num_val))),1,[]); n = length(activecols); % Compute which columns in the composite matrix get the numbers. numcols = activecols + (1:2:2*n); % Compute which columns in the composite matrix get the number of digits. ndigcols = numcols + 1; % Compute which columns in the composite matrix get chars. charcols = true(1,max_len + 2*n); charcols(numcols) = false; charcols(ndigcols) = false; % Create and fill composite matrix, comp. comp = zeros(num_str,max_len + 2*n); comp(:,charcols) = double(s1); comp(:,numcols) = num_val(:,activecols); comp(:,ndigcols) = num_dig(:,activecols); % Sort rows of composite matrix and use index to sort c in ascending or % descending order, depending on mode. [unused,index] = sortrows(comp); if is_descend index = index(end:-1:1); end index = reshape(index,size(c)); cs = c(index);

参考：https://ww2.mathworks.cn/matlabcentral/fileexchange/10959-sort_nat-natural-order-sort

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