mat_mult

mat_mult.sql

# Calculate X * X

create table XtX (row_num int, col_num int, value int);
insert into XtX
select f1.col_num row_num
     , f2.col_num col_num
     , sum(f1.feature_value * f2.feature_value) value
from features f1
join features f2
on f1.row_num = f2.row_num
group by f1.col_num, f2.col_num;


#Calculate X * Y

create table XtY (row_num int, col_num int, value float);
insert into XtY
select f.col_num row_num
     , l.col_num col_num
     , sum(f.feature_value * l.label_value) value
from features f
join labels l
on f.row_num = l.row_num
group by f.col_num, l.col_num;