Index Matrix A and Matrix B Problems

2 次查看（过去 30 天）
jane
jane 2022-6-24
编辑： Dhritishman 2022-7-3
i have matrix A and Matrix B
A = [[ 0, 1, 1, 0, 1, 0,1],
[ 0, 0, 1, 1, 0, 0,0],
[ 1, 1, 0, 1, 1, 0,0]],
B = [[ 234, 59, 15, 99, 61, 74 ,71],
[ 16, 27, 14, 13, 111, 345.67],
[ 54, 23, 16, 14, 13, 27,100]],
How to make the value in matrix B be 0 if the value in matrix A is 1.
For example, in matrix A (row 1, column 2), the value of 1 in matrix B (row 1, column 2) will be 0.
I tried using loop but it didn't work. Thank you

请先登录，再回答此问题。

回答（3 个）

James Tursa
James Tursa 2022-6-24
编辑：James Tursa 2022-6-24
You can use logical indexing:
B(A==1) = 0;
You can use a loop for this also, but you would have to show us the code you used before we can tell you what you did wrong with that approach.
  3 个评论
显示 1更早的评论
James Tursa
James Tursa 2022-6-24
If on the other hand you want the A==1 spots to contain original B values and the other spots to become zero, then simply change the comparison operator used from "equals" to "not equals":
B(A~=1) = 0;

请先登录，再进行评论。

Voss
Voss 2022-6-24
Ran in:
A = [ 0, 1, 1, 0, 1, 0,1; 0, 0, 1, 1, 0, 0,0; 1, 1, 0, 1, 1, 0,0]
A = 3×7
0 1 1 0 1 0 1 0 0 1 1 0 0 0 1 1 0 1 1 0 0
B = [ 234, 59, 15, 99, 61, 74 ,71; 16, 27, 14, 13, 111, 345,67; 54, 23, 16, 14, 13, 27,100]
B = 3×7
234 59 15 99 61 74 71 16 27 14 13 111 345 67 54 23 16 14 13 27 100
B(A == 1) = 0
B = 3×7
234 0 0 99 0 74 0 16 27 0 0 111 345 67 0 0 16 0 0 27 100
  4 个评论
显示 2更早的评论

请先登录，再进行评论。

Dhritishman
Dhritishman 2022-7-3
编辑：Dhritishman 2022-7-3
Ran in:
MATLAB provides logical indexing which can be used to select or modify elements of a matrix.
A = [0, 1, 1, 0, 1, 0, 1; 0, 0, 1, 1, 0, 0,0; 1, 1, 0, 1, 1, 0,0]
A = 3×7
0 1 1 0 1 0 1 0 0 1 1 0 0 0 1 1 0 1 1 0 0
B = [234, 59, 15, 99, 61, 74, 71; 16, 27, 14, 13, 111, 345, 67; 54, 23, 16, 14, 13, 27, 100]
B = 3×7
234 59 15 99 61 74 71 16 27 14 13 111 345 67 54 23 16 14 13 27 100
% This line of code changes the value in matrix B to 0 if the value of the corresponding element in matrix A is 1.
B(A == 1) = 0
B = 3×7
234 0 0 99 0 74 0 16 27 0 0 111 345 67 0 0 16 0 0 27 100

类别

在 Help Center 和 File Exchange 中查找有关 Matrix Indexing 的更多信息

标签

产品


版本

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by