how to find out how many times a number apears in a 2D matrix ? which function to use?
2 次查看(过去 30 天)
显示 更早的评论
Hey,
how can I find how many time a numbers appears in an 2D matrix for example:
If I have a matrix
x=[1,3,4;2,2,1;2,2,1]
number 2 appears 4 times
numger 1 appears 2 times
number 3 appears 1 time
Desired output:
22 1 3
22 1
1 个评论
Image Analyst
2019-1-7
编辑:Image Analyst
2019-1-7
You can't have an array with ragged right edge. Arrays must be rectangular. What do you want in the space below the 3? Or else you could have a 1-by-3 cell array, ca where
ca{1} = [2, 2; 2, 2];
ca{2} = [1;1];
ca{3} = 3;
Is that what you want?
Anyway, 1 appears 3 times, not 2 times, and what about 4? Why is 4 not in your desired output?
采纳的回答
madhan ravi
2019-1-5
n=2; % number to be tested
nnz(ismember(x,n))
2 个评论
madhan ravi
2019-1-7
编辑:madhan ravi
2019-1-7
Try the below , a in result represent unique numbers and the corresponding histc() shows how many times they occur in the matrix:
a = unique(x);
result = [a histc(x(:),a)]
更多回答(1 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Logical 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!