Randomly change certain characters of a character matrix

Question

Nick DeMarchis 2019-5-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/463297-randomly-change-certain-characters-of-a-character-matrix

编辑： Adam 2019-5-21

Hi there! I have a very large (~300,000 by 16) character vector. How could I insert a section that randomly changes, say 1000 of the characters (not lines) to some other character that I define? Thank you!

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Adam Danz 2019-5-21

I'd start here.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Adam 2019-5-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/463297-randomly-change-certain-characters-of-a-character-matrix#answer_376025

编辑：Adam 2019-5-21

在 MATLAB Online 中打开

If you mean basic letters, then e.g.

idx = randi( numel( yourCharArray ), 1000, 1 );
replacementChars = char( randi( 26, 1000, 1 ) + 96 );
yourCharArray( idx ) = replacementChars;

would replace them with lower case letters from 'a' to 'z'.

If you want other characters then you can change the hard-coded 26 and 96 there as appropriate to index into the ascii character set. 26 obviously represents the 26 letters of the alphabet and 'a' is represented by ascii 97. The random integers will be created from 1 to 26 to add to this.

If you want to you can be fussier to ensure that all your 1000 indices are unique also, but I shall leave that for you.