Question

给定矩阵： - A = [0 1 2 3 4 5];

我想将其转换为字符串单元格数组：A = {'0' '1' '2' '3' '4' '5'};

我可以使用以下方式执行此操作：

A = [0 1 2 3 4 5];

for i=1:6
    A1{i}= num2str(A(i));
end
A1

我希望以更简单的方式做到这一点而没有循环。

Answer 1

使用num2str和strsplit的另一种方法：

A1 = strsplit(num2str(A))

Answer 2

您可以将arrayfun与anonymous function结合使用：

B = arrayfun(@(x) {num2str(x)}, A);

cellfun有点快，也很好用：

B = cellfun(@num2str, num2cell(A), 'uni', 0);

最快的解决方案是此solution的改进版本（归功于obchardon）

B = regexp(num2str(A), '\s+', 'split');

Answer 3

以下解决方案大致从最快到最慢排序。请注意解决方案如何分为三个数量级的性能等级。

这是在iMac上使用来自MacPorts的预编译Octave 4.2.2; octave @4.2.2_1+accelerate+app+docs+fltk+gfortran+graphicsmagick+qt5+sound。

Elapsed time is 0.00452113 seconds.
Elapsed time is 0.0121579 seconds.
Elapsed time is 0.0185781 seconds.
Elapsed time is 0.0243361 seconds.
Elapsed time is 0.025944 seconds.
Elapsed time is 2.42572 seconds.
Elapsed time is 2.4809 seconds.
Elapsed time is 2.48733 seconds.
Elapsed time is 2.49299 seconds.

Takeaways：优先sprintf优先于任何其他字符串转换，ostrsplit优先于strsplit。

clear all
A=rand(1,2000);
#A=1:2000;

tic
A4=ostrsplit(sprintf("%g ",A), " ", true);
toc;tic

A9=ostrsplit(num2str(A), " ", true);
toc;tic

A8=regexp(num2str(A), '\s+', 'split');
toc;tic

A3S=num2str(A');
A3=mat2cell(A3S,ones(1,size(A3S,1)))';
A3=strtrim(A3);
toc;tic

A5=strsplit(num2str(A));
toc;tic

A7=cellfun(@num2str, num2cell(A), 'uni', 0);
toc;tic

A6=arrayfun(@(x) {num2str(x)}, A);
toc;tic

A2=cell(size(A));
for i = 1:numel(A)
  A2{i} = num2str(A(i));
endfor
toc;tic

for i = 1:numel(A)
  A1{i} = num2str(A(i));
endfor
toc;tic

将数值数组转换为字符串单元格数组

3 个答案: