Matlab - count how many times a number occurs

MATLAB
Thread starter jemma
Start date Aug 17, 2010
Tags

Count Matlab

In summary, to count the occurrences of a specific number, 'x', in an array 'A' using Matlab, you can use the 'sum' function with the syntax 'sum(A == x)'. This can also be used to count the occurrences of multiple numbers by using logical operators. To count the occurrences of a number within a specific range, you can use the syntax 'sum(A >= 1 & A <= 10 & A == x)'. To count the occurrences of a number in a matrix, you can use the 'sum' function with the '(:)' operator. And to count the occurrences of a number in a cell array, you can use the syntax 'sum(strcmp(C,x))'.

Aug 17, 2010

jemma

Suppose

x =

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

I need a function to count how many times each set of number occurs
eg.
1 2 3 4 occurs 3 times
5 6 7 8 occurs 2 times

Thanks!

Last edited: Aug 17, 2010

Physics news on Phys.org

Aug 17, 2010

NeoDevin

Off the top of my head, you could try:

sum(x == 2)

To count the number of times 2 appears.

1. How do I count the number of times a specific number occurs in a given array using Matlab?

To count the occurrences of a specific number, say 'x', in an array 'A', you can use the 'sum' function in Matlab. The syntax would be: sum(A == x). This will return the number of times 'x' occurs in the array 'A'.

2. Can I count the occurrences of multiple numbers in one go using Matlab?

Yes, you can count the occurrences of multiple numbers by using the 'sum' function with logical operators. For example, to count the occurrences of numbers 2, 4, and 6 in an array 'A', you can use the syntax: sum(A == 2 | A == 4 | A == 6). This will return the total count of these three numbers in the array 'A'.

3. Is there a way to count the occurrences of a number in a specific range using Matlab?

Yes, you can use the 'sum' function with logical operators to count the occurrences of a number within a specific range. For example, to count the occurrences of number 'x' in an array 'A' within the range of 1 to 10, you can use the syntax: sum(A >= 1 & A <= 10 & A == x). This will return the number of times 'x' occurs within the specified range in the array 'A'.

4. What if I want to count the occurrences of a number in a matrix in Matlab?

To count the occurrences of a number in a matrix, you can use the 'sum' function with the '(:)' operator. This will convert the matrix into a single column vector and then you can use the 'sum' function as mentioned in the previous questions to count the occurrences of a number in the matrix.

5. Can I count the occurrences of a number in a cell array using Matlab?

Yes, you can use the 'sum' function with logical operators to count the occurrences of a number in a cell array. However, the syntax would be slightly different. For example, to count the occurrences of number 'x' in a cell array 'C', you can use the syntax: sum(strcmp(C,x)). This will return the total count of 'x' in the cell array 'C'.