groupby
groupby(tbl,cols,ops) applies a reduction operation to table tbl based on the columns specified in cols and the operation(s) specified in ops.
Available operations: sum, prod, mean, min, max.
Available operations: sum, prod, mean, min, max.
Examples
> tbl = table({'Boston'; 'San Diego'; 'Boston'}, [1500; 250; 100], 'VariableNames', {'Store', 'Sales'})#
Store Sales
Boston 1500
San Diego 250
Boston 100
> groupby(tbl, 'Store', 'sum')#
Store Sales
Boston 1600
San Diego 250
> tbl = table({'May'; 'June'; 'May'}, {'Boston'; 'San Diego'; 'Boston'}, [1500; 250; 100], [4; 3; 3], 'VariableNames', {'Date', 'Store', 'Sales', 'People'})#
Date Store Sales People
May Boston 1500 4
June San Diego 250 3
May Boston 100 3
> groupby(tbl,{'Store','Date'},'sum')#
Date Store Sales People
May Boston 1600 7
June San Diego 250 3
> t = table({'Maths'; 'Phisics'; 'Maths'; 'Maths'; 'Phisics'}, {'Anne'; 'Peter'; 'Anne'; 'Peter'; 'Peter'}, [7; 6; 8; 9; 10], [0.1; 0.2; 0.1; 0.1; 0.2], 'VariableNames', {'Subject', 'Student', 'Exam', 'Points'})#
Subject Student Exam Points
Maths Anne 7 0.1
Phisics Peter 6 0.2
Maths Anne 8 0.1
Maths Peter 9 0.1
Phisics Peter 10 0.2
> groupby(t,{'Subject','Student'},{'mean','sum'})#
Subject Student Exam Points
Maths Anne 7.5 0.2
Maths Peter 9 0.1
Phisics Peter 8 0.4
Resources
