Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
529 views
in Technique[技术] by (71.8m points)

matlab - Difference between append and x = [x, element]

I've create an array X as X = [1 2 3 4 5] and I want to insert 0 at the end of it.

Is there any difference in using X = [X, 0] and X = append(X, 0)?

I didn't find anything about and I'm not sure if I can notice the difference.

Thanks in advance!

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

As explained in the other answer, append is part of a toolbox, and not available to everyone.

The correct way to append to a matrix, however, is

X(end+1) = 0;

This is a whole lot more efficient than X=[X,0]. The difference is that this latter form creates a new array, and copies the original one into it. The other form simply appends to the matrix, which usually doesn't require reallocation. See here for an experiment that shows the difference (read the question and my answer for both parts of the experiment).


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...