Acme-Tools

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Tools.pm  view on Meta::CPAN

 75            46.5                          41.5
 99            1372.19                       943.93
 100           1429                          992

Found like this:

 perl -MAcme::Tools -le 'print for percentile([0,1,25,50,75,99,100], 1,4,6,7,8,9,22,24,39,49,555,992)'

And like this in Oracle-databases:

 select
   percentile_cont(0.00) within group(order by n) per0,
   percentile_cont(0.01) within group(order by n) per1,
   percentile_cont(0.25) within group(order by n) per25,
   percentile_cont(0.50) within group(order by n) per50,
   percentile_cont(0.75) within group(order by n) per75,
   percentile_cont(0.99) within group(order by n) per99,
   percentile_cont(1.00) within group(order by n) per100
 from (
   select 0+regexp_substr('1,4,6,7,8,9,22,24,39,49,555,992','[^,]+',1,i) n
   from dual,(select level i from dual connect by level <= 12)
 );

(Oracle also provides a similar function: C<percentile_disc> where I<disc>
is short for I<discrete>, meaning no interpolation is taking
place. Instead the closest number from the data set is picked.)

=cut

sub percentile {
  my(@p,@t,@ret);

Tools.pm  view on Meta::CPAN

=head2 cart

Cartesian product

B<Easy usage:>

Input: two or more arrayrefs with accordingly x, y, z and so on number of elements.

Output: An array of x * y * z number of arrayrefs. The arrays being the cartesian product of the input arrays.

It can be useful to think of this as joins in SQL. In C<select> statements with
more than one table behind C<from>, but without any C<where> condition to join the tables.

B<Advanced usage, with condition(s):>

B<Input:>

- Either two or more arrayrefs with x, y, z and so on number of elements.

- Or coderefs to subs containing condition checks. Somewhat like C<where> conditions in SQL.

Tools.pm  view on Meta::CPAN

  return $proc->();
}


=head2 pivot

Resembles the pivot table function in Excel.

C<pivot()> is used to spread out a slim and long table to a visually improved layout.

For instance spreading out the results of C<group by>-selects from SQL:

 pivot( arrayref, columnname1, columnname2, ...)

 pivot( ref_to_array_of_arrayrefs, @list_of_names_to_down_fields )

The first argument is a ref to a two dimensional table.

The rest of the arguments is a list which also signals the number of
columns from left in each row that is ending up to the left of the
data table, the rest ends up at the top and the last element of

Tools.pm  view on Meta::CPAN

  $Dbh->disconnect;
  $Dbh=pop@Dbh if @Dbh;
}
sub drow {
  my($q,@b)=_dattrarg(@_);
  #my $sth=do{$Sth{$Dbh,$q} ||= $Dbh->prepare_cached($q)};
  my $sth=$Dbh->prepare_cached($q);
  $sth->execute(@b);
  my @r=$sth->fetchrow_array;
  $sth->finish if $$Dbh{Driver}{Name} eq 'SQLite';
  #$dbh->selectrow_array($statement);
  return @r==1?$r[0]:@r;
}
sub drows {
}
sub drowc {
}
sub drowsc {
}
sub dcols {
}

t/24_db.t  view on Meta::CPAN

    a integer primary key,
    b varchar2,
    c date
  )

ddo("insert into tst values ".
      join",",
      map "(".join(",",$_,$_%2?"'XYZ'":"'ABC'",time_fp()).")",
      1..100);
dcommit();
ok( 100 == drow("select sum(1) from tst") );
ok( 50 == drow("select sum(1) from tst where b = ? and c <= ?", 'ABC',time_fp()) );
ok( 50 == drow("select sum(1) from tst where b = ? and c <= ?", 'XYZ',time_fp()) );
ok(1);
dlogout();