How to bin a simple number array?

Hello,

I'm reading a simple number array from a .txt file (all integers) using:

fileID = fopen('control.txt','r');
formatSpec = '%d';
A = fscanf(fileID,formatSpec);

Now I want to bin these integers into a several groups:

Group 1: integers from 21 to 100;
Group 2: integers from 101 to 500;
Group 3: integers from 501 to 1000;
Group 4: integers from 1001 to infinity (max number unknown).

I'm also interested in finding the range (how many numbers) of each group.

Thank you!

Answer 1

[Azzi Abdelmalek]

A=1:120
[b,c]=histc(A,[21 50 60 100 inf])
out=accumarray(c'+1,(1:numel(c))',[],@(x) {A(x)})
out=out(2:end)
celldisp(out)

[That One]

Hi Azzi,

Thanks for the quick answer. I'm actually trying to bin my number array into 4 groups and write the 4 groups into 4 .txt files as:

fileID = fopen('Group_1.txt','w');

fprintf(fileID, '%d\r\n',B);

fclose(fileID);

All I'm missing is the code to bin these numbers. Can you please show me how to do that? Thanks a lot!

Answer 2

[Steven Lord]

Use the histcounts function and specify a vector of edges.

[That One]

How do I specify a vector of edges? Can you please be more specific? Thanks!

[Steven Lord]

Take a look at the documentation for histcounts for some examples.

[Star Strider]

You have already come close to defining them:

Group 1: integers from 21 to 100;
Group 2: integers from 101 to 500;
Group 3: integers from 501 to 1000;
Group 4: integers from 1001 to infinity (max number unknown).

Use the max function to help you define the upper edge.

Experiment with to get the result you want.

[Steven Lord]

Or just specify Inf as the right endpoint of the last bin.