Number of occurrences per category per month using table data

I am trying to use this table to figure out how many of the subCategory occur within a month time span. The data comes with date times such as below:

'01-Oct-2008'

'02-Oct-2008'

'07-Oct-2008'

'08-Oct-2008'

The time span is 137 months past Oct-2008 (AKA, Present Year)

What I would like to do is write a command that looks at the all the entries in the month of October 2008. Then tells me the number of occurrences that each of the sub-categories have. Once that processes is done, advance to the next month and repeat for the next 136 months. I figure a for loop that can step each month, but the datetime indexing wants the date and month. Perhaps removing the date and just having the month would do it? But how would the for loop advance one month? Below is how the raw table is currently being used in Matlab.

%% Raw Data Table
VariableNames = ["FirmName", "City", "State", "CountryArea", "InspectionEndDate", "ProgramArea", "CFRActNumber", "Category", "SubCategory", "SubsubCategory", "AbsenceofManagementStructure", "IncorrectImplementation", "ShortDescription", "EndofLongDescription", "LongDescription", "Characters"];
VariableTypes = ["categorical", "categorical", "categorical", "categorical", "datetime", "categorical", "categorical", "string", "categorical", "string", "string", "string", "string", "string", "string", "double"];
FullDataSet = table('size',[1,16],'VariableNames', VariableNames, 'VariableTypes',VariableTypes)
%% Categories 
c ={'Design Quality','Employee Performance','Employee Training','Management for Quality','Management of Data','Performance Planning Process','Process Management','Quality Assessment','Supplier Quality','Support Services Management'};
SubCategoryValues = categorical (c);

I've tried to turn the table "FullDataSet" into a timeseries table, but I couldn't figure out how to get all the entries for a given month out. The resulting table I'm after looks like this:

%% Desired Table post processing
VariableNames2 = ["Month","Design Quality","Employee Performance","Employee Training","Management for Quality","Management of Data","Performance Planning Process","Process Management","Quality Assessment","Supplier Quality","Support Services Management"];
VariableTypes2 = ["datetime","double","double","double","double","double","double","double","double","double","double"];
InspectionsPerMonth = table('size',[1,11],'VariableNames', VariableNames2, 'VariableTypes',VariableTypes2)

I will then take 'InspectionsPerMonth' and make graphs from it.

I've tried ismember(, dateshift(, and a for loop. Due to the many different types of data in the table(FullDataSet), some of the indexing commands don't work.

Any articles or pointers that can help me would greatly appreciated.

Answer 1

[Seth Furman]

Check out the groupsummary function.

https://www.mathworks.com/help/matlab/ref/double.groupsummary.html

>> rng default
>> Weather = categorical(["rain","shine"])

Weather = 

  1×2 categorical array

     rain      shine 

>> Weather = Weather(randi(2,1,62))';
>> t = timetable((datetime('01-Oct-2008'):days(1):datetime('01-Dec-2008'))',Weather);
>> head(t)

ans =

  8×1 timetable

       Time        Weather
    ___________    _______

    01-Oct-2008     shine 
    02-Oct-2008     shine 
    03-Oct-2008     rain  
    04-Oct-2008     shine 
    05-Oct-2008     shine 
    06-Oct-2008     rain  
    07-Oct-2008     rain  
    08-Oct-2008     shine 

>> groupsummary(t,["Time","Weather"],["month","none"])

ans =

  5×3 table

    month_Time    Weather    GroupCount
    __________    _______    __________

     Oct-2008      rain          10    
     Oct-2008      shine         21    
     Nov-2008      rain          17    
     Nov-2008      shine         13    
     Dec-2008      rain           1