How to count instances of values in a table?

How can I make the following code more efficient? This current version takes incredibly long to run on my large table. The goal of the code is to assign the position each row appears in a table, where the table dates are sorted from newest to oldest.

For example, if

%input data sample

call_summary =

6×3 table

Symbol Date BDTE

______ ______ ______

AAPL 12/16/2022 7

AAPL 12/16/2022 14

AAPL 12/09/2022 7

AAPL 12/09/2022 14

AAPL 12/09/2022 21

AAPL 12/02/2022 7

AAPL 12/02/2022 21

%current code below

call_height = height(call_summary);

count_call = zeros(call_height,1);

parfor h = 1:call_height

count_call(h) = sum((call_summary.Symbol == call_summary{h,'Symbol'}).*(call_summary.BDTE == call_summary{h,'BDTE'}).*(call_summary.Date >= call_summary{h,'Date'}));

end

%output data sample

count_call =

6×1 table

Count

______

1 %First occurance of BDTE = 7 for AAPL, where dates sorted newest to oldest

1 %First occurance of BDTE = 14 for AAPL, where dates sorted newest to oldest

2 %Second occurance of BDTE = 7 for AAPL, where dates sorted newest to oldest

2 %Second occurance of BDTE = 14 for AAPL, where dates sorted newest to oldest

1 %First occurance of BDTE = 21 for AAPL, where dates sorted newest to oldest

3 %Third occurance of BDTE = 7 for AAPL, where dates sorted newest to oldest

2 %Second occurance of BDTE = 21 for AAPL, where dates sorted newest to oldest

Answer 1

[Voss]

call_summary = table( ...
    {'AAPL';'AAPL';'AAPL';'AAPL';'AAPL';'AAPL';'AAPL'}, ...
    {'12/16/2022';'12/16/2022';'12/09/2022';'12/09/2022';'12/09/2022';'12/02/2022';'12/02/2022'}, ...
    [7;14;7;14;21;7;21], ...
    'VariableNames',{'Symbol','Date','BDTE'})

call_summary = 7×3 table
     Symbol          Date         BDTE
    ________    ______________    ____

    {'AAPL'}    {'12/16/2022'}      7 
    {'AAPL'}    {'12/16/2022'}     14 
    {'AAPL'}    {'12/09/2022'}      7 
    {'AAPL'}    {'12/09/2022'}     14 
    {'AAPL'}    {'12/09/2022'}     21 
    {'AAPL'}    {'12/02/2022'}      7 
    {'AAPL'}    {'12/02/2022'}     21 

count_call = zeros(size(call_summary,1),1);
g = findgroups(call_summary(:,{'Symbol','BDTE'}));
for ii = 1:max(g)
    count_call(g == ii) = 1:nnz(g == ii);
end

disp(count_call);

     1
     1
     2
     2
     1
     3
     2