How to add lower triangle of zeros/indent to each row, in a matrix?

Question

Amanda 2021-4-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/812800-how-to-add-lower-triangle-of-zeros-indent-to-each-row-in-a-matrix

评论： Amanda 2021-4-25

I have this matrix:

2 3 4 5 6 7 8 5 5
3 3 3 3 4 4 4 5 5
4 3 4 3 4 4 4 5 5
3 3 3 4 4 4 5 5 5 

And I want this as the result:

2 3 4 5 6 7 8 5 5 0 0 0
3 3 3 3 3 4 4 4 5 5 0 0
0 1 4 3 4 3 4 4 4 5 5 0
0 0 3 3 3 3 4 4 4 5 5 5 

How can I do this as a script?

Please help

Thank you

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Catalytic 2021-4-25

It appears that you have not Accept-clicked any of the answers you have been given to your other questions.

Were they all unhelpful?

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Matt J 2021-4-25

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/812800-how-to-add-lower-triangle-of-zeros-indent-to-each-row-in-a-matrix#answer_684340

编辑：Matt J 2021-4-25

在 MATLAB Online 中打开

B=[1 2 3 4 5 6 7 8 5 5
3 3 3 3 3 4 4 4 5 5
1 4 3 4 3 4 4 4 5 5
3 3 3 3 4 4 4 5 5 5];
[m,n]=size(B);
result=spdiags(B,0:n-1,m,n+m-1);
full(result)
ans = 4×13
     1     2     3     4     5     6     7     8     5     5     0     0     0
     0     3     3     3     3     3     4     4     4     5     5     0     0
     0     0     1     4     3     4     3     4     4     4     5     5     0
     0     0     0     3     3     3     3     4     4     4     5     5     5