How can one reshape this table?

Consider a table T with

group          date        visitor
age 18-24  1/1/2021 10
age 18-24  1/2/2021  20
age 25-34 1/1/2021  10
age 25-34  1/2/2021 30

I want to reshape the matrix as

date   age18-24 age 25-34
1/1/2021   10     10
1/2/2021   20     30

How can one do this?

Answer 1

[Matt J]

Perhaps as follows?

load tst

T

T = 4×3 table
        group            date        visitor
    _____________    ____________    _______

    {'age 18-24'}    {'1/1/2021'}      10   
    {'age 18-24'}    {'1/2/2021'}      20   
    {'age 25-34'}    {'1/1/2021'}      10   
    {'age 25-34'}    {'1/2/2021'}      30   

[Gage,IDage]=findgroups(T(:,1));

[Gdate,IDdate]=findgroups(T(:,2));

Tnew=[ IDdate, array2table( accumarray([Gdate,Gage],T{:,3}) , 'Var',IDage{:,1})]

Tnew = 2×3 table
        date        age 18-24    age 25-34
    ____________    _________    _________

    {'1/1/2021'}       10           10    
    {'1/2/2021'}       20           30