Count number of values of a Matrix inside a range and plot it

Hi!

I have a matrix A which dimension is 100 X 100.

I filtered A in order to obtain its values less than 15 and I obtain matrix B.

B=A;
indices = find(abs(B)>15);
B(indices) = NaN;

I would like to know how to obtain the number of values in B in the folowing ranges:

Number of values of B between 5 and 15
Number of values of B between 4 and 5
Number of values of B between 3 and 4
Number of values of B between 0 and 3

Finally I would like to plot these (numbers of values in these ranges) in a bar graph or hist graph.

Thank you!!

Answer 1

[Adam Danz]

bins = [0,3,4,5,15];  
h = histogram(B(:),bins); 

To get the counts within each bin,

h.Values 

[Andrea Mira]

Could you indicate me how to use "h.Values"?

Thanks!

[Adam Danz]

My answer shows you how.

You can also read about this property here.

h is the output to histogram

% h = histogram(_____); 

h.Values are the heights of each bar

Demo:

h = histogram(randi(5,1,10));

h.Values

ans = 1×5

4 1 2 1 2

The height of the first bar is 4, second bar is 1, etc.

[Andrea Mira]

Thanks, that's what I want

and sorry for the inconvenience

[Adam Danz]

No problem.

When using histogram (or histcounts) to count binned data, remember these points summarized from the documentation.

1. For a bin [a,b], data are counted if a <= data < b so values that are equal to the upper bound of the bin are not counted in the bin.
2. The last bin behaves differently. For bin [a,b], data are counted if a <= data <= b as is shown below.

bins = [1 2 3 4];
data = [1.0 1.5 2.0 2.5 3.0 3.5 4.0];
histogram(data, bins)

A solution to get around this problem is to add another bin:

bins = [1 2 3 4 5];
histogram(data, bins)