How do i count unique elements in two table columns?

Dear all;

for the following table:which include student name, class and school name ..

std_name      class       School 
A1              1           Art
A2              1           Art
A3              1           Muc
A4              2           muc
A5              3           Art
A6              2           fun
A7              3           fun
A8              4           Muc
...

i need to count : - how many student in every class, then write new table includes the following result as example: class number and how many student in every class, then names of schools... as shown below:

class     No. of std         School 
1           50               Art, Muc
2           30               muc, fun
3           10               Art, fun
4           100              muc 
etc..
-

Answer 1

[Guillaume]

Simpler, using rowfun which did exist in R2015a:

out = rowfun(@(school) {strjoin(unique(school), ', ')}, A, ...
             'GroupingVariables', 'class', 'InputVariables', 'School')

[ahmed obaid]

thanks a lot for all experiences ...

Answer 2

[Andrei Bobrov]

A = readtable('A.csv');
A.Properties.VariableNames = {'std_name','class','School'};

[g,ii] = findgroups(A.class);
out = table(ii,accumarray(g,1),splitapply(@(x){strjoin(unique(x),',')},A.School,g),...
                                                 'var',{'class','No_of_std','School' });

[ahmed obaid]

• Undefined function or variable 'findgroups'??
• Undefined function or variable 'splitapply'??

 i'm using matlab 2015.. thanks

[Star Strider]

Both of those functions were introduced in R2015b.

[ahmed obaid]

this is my installing directory... is there any difference between a and b? matlab version..

    \MATLAB Production Server\R2015a

i would thank any one can gibe me link to download it..

[Guillaume]

You download R2015b like you download any other releases, directly from the mathworks site:

https://www.mathworks.com/downloads/web_downloads/download_release?release=R2015b

To see what's new in R2015b: https://uk.mathworks.com/help/releases/R2015b/matlab/release-notes.html#R2015b

But if you're going to upgrade, you'd be better off moving to the latest version: 2017a

[ahmed obaid]

Perhaps ... modified code to earlier version.. upgrades is not available currently.. thanks