Count number of elements in a matrix more or less than given numbers

Question

Meg Cullen 2019-5-16

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https://ww2.mathworks.cn/matlabcentral/answers/462501-count-number-of-elements-in-a-matrix-more-or-less-than-given-numbers

回答： Keshav Anirudh 2023-6-22

采纳的回答： Kevin Phung

I want to count number of elements in the 2nd column of a matrix more or less than given numbers x and y.

For example, In the matrix A, x=20 and y=10.Thus the count of numbers >20 and <10 (i.e not between 10 to 20) is 5

A =

1 23

2 9

3 55

4 78

5 16

6 11

7 1

How to construct this code?

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Answer 1

Kevin Phung 2019-5-16

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https://ww2.mathworks.cn/matlabcentral/answers/462501-count-number-of-elements-in-a-matrix-more-or-less-than-given-numbers#answer_375339

编辑：Kevin Phung 2019-5-16

在 MATLAB Online 中打开

x = 10;
y = 20;
sum(A(:,2)<x | A(:,2)>y)

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Meg Cullen 2019-5-16

Thank you :)

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Answer 2

Sulaymon Eshkabilov 2019-5-16

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/462501-count-number-of-elements-in-a-matrix-more-or-less-than-given-numbers#answer_375345

在 MATLAB Online 中打开

Hi Meg,

Here are two simple solutions to your problem:

% Given matrix:
A =[ 1    23;
     2     9;
     3    55;
     4    78;
     5    16;
     6    11;
     7     1];
  %% 1- way
 Anew = A(:,2);
 Index1 = find(Anew<10); Index2 = find(Anew>20);
 Number1  = numel(Index1)+numel(Index2);
 %% 2- way
 Number2 = numel(find(A(:,2)<10))+numel(find(A(:,2)>20));
 
 