# How to bin a variable and create new variables for each bin

6 views (last 30 days)
Anaya Kharwadkar on 8 Nov 2020
Commented: Steven Lord on 12 Nov 2020
Name = [Alice Bob Cate Doug Ernest Fan]
Age = [23 15 24 32 44 22]
T = table(Name,Age)
I want to create bins for the variable Age: for eg: 0-10, 11-20, 21-30 and 31-40
Then I want to sort the whole table based on the bins.
Thus, I want to get 4 different tables based on the Age bins

Mathieu NOE on 9 Nov 2020
hello
below an example for the first bin, easy to duplicate for the other ones
Name = [{'Alice'} {'Bob'} {'Cate'} {'Doug'} {'Ernest'} {'Fan'}];
Age = [23 5 24 32 44 22];
% I want to create bins for the variable Age: for eg: 0-10, 11-20, 21-30 and 31-40
% Then I want to sort the whole table based on the bins.
% Thus, I want to get 4 different tables based on the Age bins
% bin1
age_range1 = [0 10];
ind = find(Age>=age_range1(1) & Age<age_range1(2))
T = table(Name(ind),Age(ind))

Eric Sofen on 12 Nov 2020
Edited: Eric Sofen on 12 Nov 2020
I'd encourage you to consider whether you really need separate tables for each age bin or whether you can simply add a grouping variable (using discretize) to the table and then select subsets by group when you need to do further calculations. That will all you to be able to iterate over the groups in the table rather than needing to manage a bunch of workspace variables for the different bins.
Steven Lord on 12 Nov 2020
One way of how to create the grouping variable is to use discretize:
Name = ["Alice"; "Bob"; "Cate"; "Doug"; "Ernest"; "Fan"];
Age = [23; 15; 24; 32; 44; 22];
T = table(Name,Age)
T = 6x2 table
Name Age ________ ___ "Alice" 23 "Bob" 15 "Cate" 24 "Doug" 32 "Ernest" 44 "Fan" 22
AgeRange = discretize(T.Age, [0 11:10:51], 'categorical');
T.Class = AgeRange
T = 6x3 table
Name Age Class ________ ___ ________ "Alice" 23 [21, 31) "Bob" 15 [11, 21) "Cate" 24 [21, 31) "Doug" 32 [31, 41) "Ernest" 44 [41, 51] "Fan" 22 [21, 31)
Or if you want an identifier:
gr = discretize(T.Age, [0 11:10:51]);
T.AgeCategory = gr
T = 6x4 table
Name Age Class AgeCategory ________ ___ ________ ___________ "Alice" 23 [21, 31) 3 "Bob" 15 [11, 21) 2 "Cate" 24 [21, 31) 3 "Doug" 32 [31, 41) 4 "Ernest" 44 [41, 51] 5 "Fan" 22 [21, 31) 3